Facebook has been a hot topic at Mesh 2010 with conversations about privacy concerns taking place all over the MaRS Centre.

But there is also a great deal of interest in making Facebook work as a business platform, as evidenced by Janice Diner‘s standing-room-only session “What Businesses Should Really Do With Facebook.”

Diner is a former creative director with Segal Communications and vice-president, strategy and user experience at Syncapse. She has created and executed social media campaigns for TD Canada Trust, Research in Motion and Sony’s PlayStation, among others.

In her Mesh session targeting companies that have already made inroads on Facebook, Diner started with a reminder of the basics: don’t forget your Facebook page’s message “wall.”

“The wall is still the closest touch point to your consumer,” she said.

But with new customizable tabs, a brand can also use Facebook’s expanding infrastructure to find new audiences.

Facebook’s brand pages have a series of tabs typically labeled “info,” “wall” or “photos” that let users navigate through content. By developing custom tabs, companies can add brand-relevant services.

Diner used Pantene‘s “Buy Now” tab as an example of new functionality added to a brand’s existing Facebook experience. It allows visitors to buy bottles of shampoo without leaving the site, and their choice of product is shipped directly to their home.

But the Pantene execution isn’t perfect, Diner said. “It’s not social. I can’t share it. I can’t comment on it. I can’t review it,” and therefore it misses the chance to be instantly shared with a friends list.

“That’s what you want to think about: how do I get my story and my message along that social curve,” she said.

Diner also noted Starbucks‘ custom tab that allows the coffee chain’s gift-card holders to add money to their cards. The company has indicated it will soon add the ability to put money on friends’ cards as gifts.

“About $1 billion was spent on virtual gifts in 2009. That means consumers are used to the concept of sticking their credit cards into a social network to purchase something. I really think next year we’ll be hearing about how many shoes were purchased inside Facebook.”

But as with all new digital media opportunities, Diner warned against using a copy-and-paste approach to creating new tabs. “You wouldn’t put your [direct mail] creative on television,” she said. Similarly, content should be unique and designed to work in that specific context.