Gmail has a feature called Priority Inbox, which automatically sorts your “important” emails to the top. The basic idea is that Gmail will prioritize email from senders that you interact with the most.

In order to predict which messages are important to you, Gmail uses some of the same technology that it uses to weed spam out of your Inbox. To predict which of your incoming messages are important, Gmail automatically takes into account a number of signals, including:

* Who sent the email (For example, if you email Bob a lot, it’s likely that messages from Bob are important.)
* What terms it includes (If you always read messages about soccer, a new message that contains those same soccer words is more likely to be important.)
* The actions that help us determine which people/terms are important to you include: replying, using stars, archiving, deleting (Messages you star are probably more important than messages you archive without opening.)

This is all done automatically, and no humans ever read your mail.

The takeaway for email marketers? Well, it’s kind of the same old story. Send awesome emails. If your recipients are more engaged and interact with your emails more often, you get priority. Here are some tips for sending more engaging emails…

• Get to know your engaged subscribers – segment, segment, segment
• Be more human, get more replies – be personal, not to “corporate”
• Write effective subjects lines – They won’t engage, if they don’t open it
• Test, test, test – if you email isn’t tested against the SPAM filters, it may not even get delivered

Since there are many highly intelligent experts that have spent a lot of time figuring out what subject line formats work best, let’s learn from them! Emarketer.com recently posted an article on email marketing subject lines and below are their findings.

Personalization continues to be more and more important in all areas of marketing and email marketing is no different. The words “you” and “your” top the list for most used terms in subject lines. Below is the full list but first a quick word of caution – some of these words can be flags for spam so be cautious how you use them.

Review the information below and consider how it could have a positive impact on your email marketing.

Top E-Mail Subject Lines Focus on ‘You’

Marketers try for personal connection with recipients

Polls show that marketers are aiming for personalization to make their e-mails stand out in recipients’ inboxes, and the rise of social media has made many consumers expect a more personal relationship with brands. And a look at e-mail subject lines suggests marketers are following that lead.

While in November 2008, subjects with “you” and “your” barely beat out “free” offers, usage of “you” to address recipients directly rose by 2009 to appear in more than one-fifth of e-mail subjects. On the flip side, terms such as “free” and “ship” decreased in importance.

Top 10 Subject Line Terms Used by US E-Mail Marketers, November 2008 & November 2009 (% of total)

Experian’s “2010 Digital Marketer” report said this reflected the growing savvy of marketing e-mail recipients. Consumers now expect free shipping offers, which makes them less of a selling point in e-mail subject lines.

Offers of savings in general, however, remained important, and with good reason. More than one-half of adults said they were likely to open an e-mail containing promotions or coupons, and 30% said they would forward such an e-mail to others, up from 28% in 2008.

Among multichannel retailers, for example, “save,” “off” and “% off” each appeared in about 12% of subject lines. Shopping and classifieds sites saw the highest share of traffic coming from e-mail clicks, compared with other industries, at 9%.

Top 10 E-Mail Marketing Subject Line Terms Used by US Multichannel Retailers, November 2009 (% of total)

Experian also found that e-mails encouraging visits to stores increased by 50% compared with 2008. And the use of “Black Friday” and “Cyber Monday” more than doubled, as Web marketers included more Black Friday offers and consumers became more familiar with the latter term.

Keep up on the latest digital trends. Learn more about an eMarketer Total Access subscription today.

Check out today’s other article, “Social Sites Lure Users Around the Clock.”