(AP) — Facebook's stock got a boost Friday, easing a decline that has followed the company's initial public offering last month.

Shares of Facebook Inc. climbed 79 cents, or 3 percent, to close Friday at $27.10. The is still down 29 percent since its IPO price of $38. And it is down 2 percent for the week.

The stock price jump comes a day after research firm comScore previewed a report measuring the effectiveness of advertising on Facebook. The report also looked at other things brands do beyond paid advertising. Such "earned media" can include Facebook users sharing a post about the brand.

In a blog post Thursday, comScore said such earned media "is having a statistically significant positive lift on people's purchasing of a brand."

ComScore plans to release the findings on Tuesday.

Also on Thursday, Facebook started rolling out its App Center to users. It's a place where people can find Facebook apps recommended to them based on their interests, apps they have downloaded or apps that their friends like.

The App Center is a central location for Facebook applications ranging from games to music-listening services. said it does not compete with mobile app stores because it drives traffic to them.