With over180 billion emails sent and received worldwide every day in 2013, todays average inbox has become a jungle of emails, some wanted, and many unwanted.

then its understandable that the battle for our limited inbox-attention is one of the email marketers biggest challenges. If you consider that it takes just seconds for most of us to scan our inboxes and decide which emails to open, which to save for later and which to delete without even reading, www.thebestofemail.com

Typically, people who are inclined to opt-in to a newsletter in the first place will usually subscribe to more than one, so as an email marketer youd do well to presume that your competitors are vying for your subscribers attention just as fiercely as you are. www.thebestofemail.com

And since todays typical subscribers are time-poor and bestow their brand-loyalty sparingly, only the cream of email marketers will rise above the others in their ongoing quest for a guaranteed email open. www.thebestofemail.com

So what can you do to out-open your competition? For starters, you must deliver highly relevant, interesting and useful content. If you consistently send content that subscribers find valuable or entertaining, chances are that theyll grow more inclined to open your emails as a matter of habit (a.k.a. email marketing nirvana). www.thebestofemail.com

But even if a subscriber enjoys your content on a regular basis, some days his inbox is so overflowing that the sheer volume of unopened emails is enough to turn him off opening any of them. www.thebestofemail.com

That means that you cant ever rest on the laurels of your email content alone, you also need to gate it SO attractively that your subscribers wont be able to resist a peek at it. www.thebestofemail.com

That gate is your subject line, and mastering the art of writing effective subject lines is therefore one of the most important keys to boosting your email open rates. www.thebestofemail.com

Here are some tips for writing subject lines that are irresistibly inviting: www.thebestofemail.com

1. Be different. First, subscribe to your competitors newsletters to get a sense of the most common types of subject lines they use. Then, review your own subject lines and see how they stack up. What you want is to stand out by giving your subject lines an edge that the others dont have. www.thebestofemail.com

EXAMPLES (Be different) A Look Inside Our Suit Jacket Sender: Brooks Brothers Meet a Member of the Paul Mitchell Team Sender: Paul Mitchell Jessica Alba is our new guest editor! Sender: Piperlime Win 1000 Gumballs - Moosejaw Word Find Sender: Moosejaw Saving Millions Of Bottles From Our Oceans & Landfill Sender: Billabong Make-Up or Break-Up Sender: Moosejaw Let's hit 500,000. Sender: CB2 Time To Get #AerieREAL! Sender: Aerie www.thebestofemail.com

2. Make one piece of content the hero of your subject line. The visible part of a subject line is restricted in length and since too much information in a limited amount of space can be daunting to read, make things easier for your subscribers by simplifying your offering. Your newsletter may well contain more than one piece of content, but for maximum impact pick the one item you care about most and make it the hero of your subject line. www.thebestofemail.com

EXAMPLES (Make one piece of content the hero) The making of an eye-con Sender: Sephora The Truth About The 30-Hour Work Week Sender: Fast Company The science behind why diets usually don't work Sender: TED.com The Great Indoors Sender: Etsy www.thebestofemail.com

3. Make your subscribers curious. Sometimes, spelling things out directly is the most sensible strategy, but in some situations a little intrigue can be a powerful motivator to dig deeper. Using a little cryptic mystery in your subject line can be so tantalizing (if done well) that your subscribers literally wont be able to resist opening the email to see what its all about. NOTE: If youre going to use the curiosity tactic, be sure to live up to the implied intrigue in your email content. If you imply something promising in your subject line only to under- deliver once the email is opened, this tactic will lose its effect. www.thebestofemail.com

EXAMPLES (Make your subscribers curious) Which undies are you? Sender: Bonds The surprising secret to healthy hair Sender: Living Proof What could be better than Lobster & Steak? Sender: Bonefish Grill The top 10 designs of 2013. Hint: there are only 9. Sender: Threadless Easiest $10 Ever Sender: Moosejaw Whats cozy, crazy, and striped all over? Sender: Kate Spade Saturday www.thebestofemail.com

4. Be quirky or really funny. Lets face it, the average inbox isnt exactly the stuff of fun and laughter. When we see a bunch of unopened newsletters in our inbox, we usually suspect that they contain some sort of offer and we brace ourselves for the predictable marketing pitch. So when we come across a subject line thats unexpectedly funny or truly clever, its like a breath of fresh air an otherwise dull and predictable inbox. www.thebestofemail.com

The moment that the corners of our mouths begin to form a smile or blurt out a giggle in response to a funny subject line is the moment that our inclination to open the email multiplies exponentially, if for no other reason than to reward the marketers effort to entertain rather than bore us. Humour goes a long way (good humour, that is! :-) www.thebestofemail.com

EXAMPLES (Be quirky or funny) Wish You Were Beer Sender: Etsy It's a bird! It's a plane! It's... no, it's a plane. Sender: Threadless Don't go topless. Shop our tees, sweaters, and more. Sender: Rue La La Give a gift wrapped cow this Christmas Sender: Hot Rum Cow This email is bigger on the inside. Sender: Threadless It's National Men's Day - We Support Your Package! Free Brief! Sender: American Apparel We lied last time. THESE are the best Moosejaw jackets ever. Sender: Moosejaw Oil-vey Sender: Dean & DeLuca www.thebestofemail.com

5. Make it urgent. If your message is time sensitive or if you have something to promote that your subscribers would find valuable and would be upset to miss out on, then adding an element of urgency to your subject line is appropriate and can be very effective. A few caveats to this tip though: www.thebestofemail.com

1. Use it sparingly. If you use the element of urgency too frequently, subscribers will learn to anticipate that most your emails seem to be urgent, and once urgency becomes the norm it will lose its effect. www.thebestofemail.com

2. Use it honestly. Dont abuse the element of urgency by applying it to promotions that arent all that urgent, because this too will ruin the effect for promotions that genuinely are urgent. Something that may seem like a priority for you as the promoter may not seem so urgent to your subscribers, so consider carefully whether the element of urgency is truly appropriate before you use it. www.thebestofemail.com

3. Be creative, not predictable. So many subject lines these days begin with frenzied pleas like Dont miss out!, Last chance! and the all-annoying Hurry!, that their excessive overuse actually diminishes the sense of urgency instead of increasing it. So to give credibility to the element of urgency in your subject lines, be creative and try to stay away from the irritatingly clichd and overused calls-to-action. www.thebestofemail.com

EXAMPLES (Make it urgent) Laneway - A Must Have Denim for Summer. Sender: Billabong Not to be dramatic, but this is your last chance. Sender: Rue La La Just in: the limited-edition Beck frames Sender: Warby Parker A $500 prize could be just a sketch away. Sender: ModCloth Vote now! Choose the #BeckhamforHM ad that will appear in the Super Bowl Sender: H&M There's an expiration date on this one Sender: Madewell www.thebestofemail.com

6. Make it conversational. Back in the early days of email marketing, subject lines used to sound relatively formal, probably because they were still regarded as just another type of correspondence via email. Happily, weve loosened up a lot since then thanks to the advent of about a million new messaging options that call for virtually no formality at all, and this informality has trickled into our inboxes too. www.thebestofemail.com

When we send and receive emails, we are after all just people trying to talk to each other, right? So sometimes the best way to connect with subscribers in the subject line is to say what you want to say as though they were right in front of you. A conversational approach makes you sound more accessible and makes the subject of the email sound more relatable. www.thebestofemail.com

EXAMPLES (Make it conversational) Repeat outfit syndrome? We understand. Sender: Madewell Yay, you signed up. Sender: TOMS One date. Two outfits. Decisions, decisions. Sender: Madewell Introducing the totes amazing new lunchbox! Sender: Smiggle Lets talk about this incredible trench Sender: Kate Spade Saturday You'll never believe who Peter's having Breakfast with? Sender: Peter Alexander www.thebestofemail.com

7. Make it bold, interesting or controversial. Ever come across a well-written teaser for a juicy piece of news or a provocative statement that didnt make you want to learn more about it? If your answer is yes then either the teaser wasnt well-written or it wasnt written in a language that you can read. www.thebestofemail.com

Subject lines that are based on a bold or interesting statement or on something that sounds controversial are a great way to pique a subscribers curiosity. But as with the caveats for some of the previous tips, this is another one that should be used sparingly. If too many of your subject lines sound controversial then eventually your subscribers might start thinking of you as nothing more than a drama queen! www.thebestofemail.com

EXAMPLES (Make it bold, interesting or controversial) IOS 7 Is Reportedly Making People Sick Sender: Fast Company Love Stinks Sender: Etsy Dudes Introducing the best-fitting pants EVER Sender: LOFT Allergic to America Sender: Narratively www.thebestofemail.com

8. Make it strike a chord. If you can make your subject line relatable to your subscribers so that they feel that you really get them, then this instant affinity can be just the thing that inspires them to open your email and check out the rest of your message. The best email marketers know their audiences well enough to understand what makes them tick, sparks their interest and inspires them into action, whether its a common concern, goal or interest. www.thebestofemail.com

EXAMPLES (Make it strike a chord) Obsessed with finding the perfect jeans? Us too. Sender: Madewell Bags, Undoubtedly a Girl's Best Friend Sender: Sambag A few tidbits on sizing & fit Sender: ModCloth When you find the one, you just know. Same goes for dresses. Sender: Rue La La Californian Camper Van Adventures? Yeah Dude Sender: Kate Spade Saturday To save or to splurge? (Insert shoulder shrug here.) Sender: Rue La La www.thebestofemail.com

9. Dont make it too salesy There are only so many subject lines containing the words 40% off! and Sale! that a typical subscriber can be bombarded with before they permanently numb his excitement over the opportunity to save because this opportunity simply repeats itself too frequently to carry any special appeal or warrant urgent action. If you care about the sanity of your subscribers and understand the merits of selling in moderation, you should apply this philosophy to your retail emails too. www.thebestofemail.com

EXAMPLES (Dont make it too salesy) The leather jacket to end all leather jackets (+ an extra 25% off sale) - Sender: Madewell 100s of dresses are here. Where are you? Sender: Rue La La more offers than you can poke a pencil at! Sender: Smiggle It pays to be a morning person. Sender: Banana Republic Dun dun dunnnnn. Sender: Rue La La This sale is undead for 9 more hours. (Then it's just dead.) Sender: Threadless A Fiver off Five Products. Sender: Firebox Groundhog, shmoundhog: 25% off what you need for spring Sender: J.Crew www.thebestofemail.com

10. Use how to, numbered lists and trending keywords. People appreciate an opportunity to learn something new about subjects that interest them, so how to subject lines (like How to write subject lines that get emails opened) and numbered list subject lines (like 11 killer tips to writing highly clickable subject lines) are still effective despite their widespread use. www.thebestofemail.com

Also, if you keep up with trending keywords that are relevant to your industry or your audience, using them in your subject lines can be a great way to add timely and topical relevance to your messages, making them a lot more appealing to click on. www.thebestofemail.com

EXAMPLES (Use how to, numbered lists and trending keywords) How to Tie a Tie Sender: Brooks Brothers The infographic guide to responsive email design Sender: Litmus 11 Expert Tips To Help You Be More Productive In 2014 Sender: Fast Company #AmericaIsBeautiful: The Coca- Cola Ad That Has Everyone Talking - Sender: Coca Cola How to nail the Slips & Camis trend Sender: Sportsgirl Get a gift for a guy & learn 3 ways to wrap it! Sender: ModCloth How to beat stage fright Sender: TED.com How chefs cut onions Sender: PureWow www.thebestofemail.com

11. Never overpromise, mislead or lie. Most of us have a very low tolerance level for email marketers who trick us into opening an email only to find that the content within isnt even remotely relevant to the premise of the subject line. The disdain we feel for the marketer or brand when this happens is usually swift and permanent. www.thebestofemail.com

As the ancient sages used to say: Open a marketing email with a bogus subject line once shame on the marketer. Open a marketing email with a bogus subject line twice shame on you! So dont fib in your subject lines (ever). www.thebestofemail.com

This presentation was created by Noya Lizor, Head Honcho at The Best of Email, a hub for showcasing standout emails by marketers who are getting email right. Visit www.thebestofemail.com to learn more about: