With the release of iTunes 9, Apple introduced a new category, Top Grossing, ranking the apps that are grossing most on the App Store. The price point that occured most today was $4.99 among these 100 apps (27 apps priced at this pricepoint in the US). However, in some countries, free apps penetrate the top grossing ranks as well.

Yes indeed, this is caused by the fact that these free apps have implemented in-app purchases, which were introduced a few days ago. This results in free apps making revenue as well, and apparently, Apple takes into account these in-app purchases for determining rankings in the Grossing lists.

According to our data, which takes into account all countries worldwide, there have been 12 free apps that entered the overall grossing list on Apple’s App Store. Comics (iTunes link), even achieved a ranking of 7 in some countries, outperforming apps such as Fifa 10 (€7.99, rank 17) and Tweetie 2 (€2.39, rank 11).

We expect more free apps to enter the top grossing lists soon, as more free apps will implement in-app purchases and consumers getting more accustomed to buying items inside apps as well.