This investment from Bezos comes just a few months after SGN raised a $15 million Series A round led by Greylock Partners and the Founders Fund.
SGN is monetizing its games mostly through advertising, but also through subscriptions and sales of virtual goods. The company's properties have about 1 million daily users, enough to make it attractive for large advertisers.
Overall, users have installed SGN games over 50 million times and handed out over 70 million gifts. It is, of course, questionable how many of these 50 million apps are still active, but with 1 million daily users, SGN is definitely one of the larger players in the casual gaming market.
Casual gaming is clearly turning into a major platform for advertisers. While both Kongregate and SGN are mostly focused on the web, the large range of casual games already available on the iPhone and other mobile devices shows that there is a very large market for them.
At the same time, though, it seems quite a few users are also very willing to actually pay for these games - as long as the prices are reasonable. As more and more investors are looking for companies that are not fully dependent on advertising for their revenue, the casual gaming market is probably going to see more investments like Bezos' in the near future.