(AP) -- PayPal is extending its reach into Facebook.

The companies said Thursday that advertisers on the world's largest online social network will be able to use Inc.'s online payments business to buy ads. The service will roll out over the next couple of weeks.

Using PayPal instead of credit cards, PayPal says, would make life easier for small international companies to buy ads on .

In addition, Facebook users will be able to use to buy Facebook Credits. These credits let users buy virtual goods on the site, like gifts or items in games.

Research firm eMarketer estimates expects ad spending on Facebook to hit $605 million this year. This would be a 39 percent increase from 2009.

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