Soldsie  lets you sell items to customers directly from your Facebook account. You post your item on Facebook. A customer sees the item, leaves a comment and can click on a link to create a Soldsie account right on your Facebook page!
They are emailed an invoice which they pay and you mail them the item.
Soldsie already has about 1,400 sellers online. The company just raised $4 million in venture funding from First Round Capital, SoftTechVC, Lerer Ventures, Correlation Ventures, Great Oaks Ventures, e.Ventures and 500 Startups, Tech Crunch reports .
This video gives a quick peak at how Soldsie works:
The extra funds will be used to hire additional staff and expand Soldsie’s services, including the addition of at least two more social platforms by the end of the year.
The service may work most effectively for small fashion brands, as a post on the official Soldsie blog explains :
“With eCommerce representing $240 billion in U.S. sales and growing 10% each year, the time is ripe for fashion retailers to learn how to sell clothes online.
Research from the Harvard Business Review tells us that while 79% of companies use, or are planning to use, social media, only 12% identify as effective users that have integrated social media into their overall growth strategy.
The good news is, selling products online has the inherent benefit of allowing your business to leverage its social media presence. Through an app like Soldsie, your fans on Facebook and Instagram can purchase a product you post just by commenting ‘sold.'”
The site provides  some case studies on businesses that have already claimed to have success with the service. They include Lubbock, TX-based boutique Polkadot Alley , which the company claims has now switched to selling only on Facebook, has eight employees, a 1,500-square-foot warehouse and is on its way to generating $1.5 million in revenue.