A new blog post at mobile apps analytics firm Flurry underscores the importance of so-called “freemium” apps at generating revenue for developers.

[ad#Google Adsense 300×250 in story]Jeferson Valadares, GM Games at Flurry, writes that his company compared the revenue generated among the top 100 grossing iOS games in January and June. The company compared “premium”-priced games – games that cost something to download, even as little as 99 cents – with “freemium” games – games that cost nothing to download, but generate revenue through in-app purchases.

In January, revenue generated from premium games made up 61 percent, while 39 percent of the revenue came from freemium games. The study revealed that between January and June, the trend had reversed itself: 65 percent of the revenue from those top selling games is from freemium titles.

Valadares called freemium “the single most dominating business model in the mobile apps industry today,” and said the trend is “undeniable and growing fast.”

Flurry’s analysis shows that the number of people who spend money in freemium games is a scant 0.5 to 6 percent of the overall user base, depending on the game. So it’s up to freemium game developers to try to get as many players as possible to download their titles to hedge their bets.

(Hat tip to GigaOM for posting about this study.)