San Francisco-based teen social network Piczo appears to have given up hope of challenging bigger rivals on its own. The five-year-old Piczo has decided to join with Stockholm-based teen-girl dress-up site Stardoll to make a joint run at the young-teen demographic. Piczo will remain an independent brand. But the two companies, along with a third, the free, ad-supported Paperdoll Heaven, are launching the Stardoll Network. It’s a play to grow its audience for advertisers targeting the young-teen demo, but also an effort to swell the base of fee-paying teens. See full story here on our sister site paidContent:UK