Yahoo is reported to be in talks to acquire social blogging service Tumblr. If a deal can't be struck to buy the site outright, Yahoo will settle for a strategic alliance and investment alternative.

According to AllThingsDigital's sources, the talks between the two are serious, while Adweek's own sources add that the buyout could reach $1 billion.

Yahoo's CEO Marissa Mayer is being cited as the main driver of the possible acquisition. AllThingsDigital claims that she has had her eye on Tumblr for some time, since she was at Google. It also reports that she has met the blogging site's founder and CEO David Karp.

Recently Yahoo's chief financial officer Ken Goldman revealed that the internet giant was looking for ways to attract more 18 to 24-year-olds. With Tumblr's social blogging and sharing focus it is believed to hit that demographic nicely.

Tumblr was formed in 2007, and since then has become home to more than 102 million blogs. They range across a huge array of subjects, with some being just locations for people to post pictures, others full personal memoirs and opinions.

"If you could pick a company that fits in with what Marissa Mayer has demonstrated in her career - aesthetics software technology and fast-growing - you could not land on a better choice," said one source.