A survey from Exact Target shows that more than half (58 percent) of consumers start their online days checking their inboxes. Marketers who use emails to reach prospective clients may find their messages will stand out when filled with information consumers want.

Custom t-shirt company Threadless' recent email campaign might be looked at as a model of success. The company recently announced it increased revenue from its email efforts by 120 percent year-over-year thanks to careful targeting and customized promotions.

Threadless' vice president of marketing, Cam Balzer, explains the campaign supported user-specific content, delivering select deals to different segments of its online community. The company launched a "Welcome Email" that allowed recipients to indicate what type of information they wanted to receive.

"By increasing the customization and functionality of our communications program, we're able to better serve our community members, learn from each user, improve the overall Threadless experience and ultimately drive sales," says Balzer.

The company also revamped its email marketing initiative by sending customers coupons relevant to their purchase histories to encourage repeat buys.

The emails are part of Threadless' larger integrated marketing efforts that support user-generated content. The company has a Facebook page, which boasts a wall covered in users' comments about its frequent deals and updates, and it has a Twitter page that responds to individual consumers' tweets.

Threadless shows that emails – like social marketing campaigns – must engage consumers and provide them with content they want. This strategy is clearly bringing the company success on the email front, and it probably translates into sales among the firm's more than 1 million Twitter followers as well.

As Brafton previously reported, Twitter users want a little more conversation from brands and successful engagement can turn social connections into customers.