Updated: Zynga Confirms Recent Purchases Of Four Mobile Gaming Companies

Now that it’s a public company, Zynga can start throwing more cash around. The online gaming company has recently acquired four small mobile gaming companies, according to a report, as it tries to build a line of business that isn’t completely dependent on Facebook.
Only one of the purchases happened recently: Reuters reported Wednesday afternoon that Zynga acquired German gaming company Gamedoctors last month. But David Ko, head of Zynga’s mobile efforts, confirmed the purchases of three other companies–HipLogic, Astro Ape, and Page44 Studios–which had been leaked or speculated upon over the last year.
The motivation for Zynga is simple: the company needs to keep coming up with hits in order to keep players on its network, both on Facebook through their PCs and Macs and through mobile games that don’t necessarily require a Facebook account, such as Words With Friends. The latter are especially compelling because Zynga can keep that usage data all to itself as well as use its own payment systems for in-app purchases.
Update: We’ve charted some of the top social gaming publishers. See how they stack up in terms of monthly active users, revenue, funding and deals: