Facebook page comments are one of the most important ways users engage with brands on the social network, but San Francisco-based startup Soldsie introduced another use for comments — as a point of sale.

Soldsie — which has been operating in stealth mode since May, under the name Central.ly — already has more than 2,000 registered users, who have processed over $750,000 in transactions through the platform.

The startup has raised some $270,000, with investors including Dave McClure, Justin Kitch, and small business web-hosting service Jimdo.

How does it work? Brands post their items, with pictures, on their pages via Soldsie, and interested Facebook users can comment “Sold!” and check out securely via PayPal.

Soldsie was co-founded by Chris Bennett and Arrel Grey, and CEO Bennett said:

Every company wants to turn their Facebook fans into paying customers, but no company has converted fan page product posts into money in the direct way that Soldsie has. With Soldsie, your fans’ comments become a social sales machine.

Readers: Which Facebook feature will be the next to be monetized?