Being a good Facebook friend isn't easy. Especially for a business trying to make the most of its online presence.

Social networks like Pinterest, Twitter, and, of course, Facebook offer a direct line of communication to your customers--and with it, a temptation to want to try to sell, sell, sell to them. But before you bombard your well-connected followers with ads, you may want to consider what it means to be a good friend to your fan base, say Eric Koger and Susan Greg Koger, co-founders of the fashion retailer ModCloth.

ModCloth, founded by the husband and wife team in 2003, is all about making friends with its customers--a strategy that appears to have served the style brand well: ModCloth made the Inc. 5000 list as America’s fastest growing retailer in 2009. Here are just a few of the innovative ways that ModCloth has gone about befriending its clientele.

Don't think in plural.

They're not just customers, they're individuals. And it helps if you think of them that way.

Eric and Susan explain that they don’t refer to ModCloth customers in plural. Instead, they use pronouns like "her" and "she" to identify the company's target audience. And while this may get confusing at all-hands meetings--almost 70 percent of the company’s employees are female, after all--it perfectly illustrates ModCloth's approach to engaging its "girl" on social media.

"We don’t see ourselves as a purveyor of specific products," says Eric. "We're very relationship based."

Susan phrases it this way: "We're the fashion company that you're friends with."

Give your business a personality.

Businesses can be people, too. But that means laying off the constant sales pitch.

Think about it, Susan says: Friends don’t tell you to buy a specific dress or piece of jewelry. They share things that they like, and pay attention to the things that you like.

In order to build more of a friend relationship with customers, ModCloth offers services outside the domain of a typical retailer, like 24/7 online access to Modcloth stylists and Google hangouts with pop culture icon Neyla Pekarek, of the indie band The Lumineers. These are the things that naturally interest the ModCloth girl, says Susan, so it makes sense for the company to share them--even when customers aren’t looking to buy.

"We want her to visit ModCloth every day. Even when she doesn’t have ten dollars in her wallet," says Susan. By offering content that builds a personality for ModCloth’s brand--even if it doesn’t actually sell a product--the company is proving that it understands and listens to its customers, she explains. And building trust with customers is the No. 1 goal.

Be a good listener.

If step one is engaging your customers, step two is actually integrating their feedback.

It's not enough to offer content and products that you think customers will like, according to the ModCloth founders. You have to let customers know that you've been listening to them, too.

ModCloth put this theory into practice last year, when the company hosted a fashion design competition called Make the Cut. After accepting more than 1,900 submissions from members of the ModCloth community, Susan posted the finalists online and allowed the ModCloth girl herself to select two winners. Those designs were then produced by a third-party manufacturer.

The reaction of the ModCloth community to this opportunity for engagement was resoundingly positive--more than 10,000 votes were cast to determine the two winners. And this seems to have set a precedent for the type of direct involvement ModCloth hopes to see from its customers. The founders expressed an interest in expanding their Google hangout series--piloted recently with Pekarek--to include the personalized and free stylist service that the company currently offers.

"Our goal is to put the customer at the center of everything we do," says Eric. And that means a lot more face time with the ModCloth girl in the future.