Hitwise UK has some interesting figures showing how effective widgets can be in driving traffic to websites from social networks.

Slide.com and RockYou, two providers of photo-sharing widgets, have moved rapidly up the rankings in the photography websites category, according to Heather Hopkins.

They have risen to numbers three and four respectively in the list of UK photo sites, just behind Photobucket and Flickr.

The figures also show how important the traffic from social networks is – last week 83% of RockYou’s traffic came directly from one; 42% from Bebo and 37% from Facebook. The pattern is the same for Slide.com, which received 43% of traffic from Facebook and 23% from Bebo.

The recent decision by Facebook to open up to widgets has clearly benefited both firms, which have among the most used widgets on the site.

Meanwhile, a market seems to be developing for Facebook applications, as they have been successful at reaching a wide audience via the site. The top 25 Facebook applications reach a combined total of 55m users.

Earlier this week, Slide.com acquired Favorite Peeps, a Facebook app with 1.3m users for $60,000, while travel company SideStep acquired Extended Info last week.

Given the relatively small prices these widgets are selling for, it’s likely that we will see more of these deals as companies try to buy their way to the top on social networks.

Further reading:

Facebook’s popularity drive continues in UK