The statistics are about what I would expect. There is no way to try most games being sold online except to download them. You can't try them in the store. If you could, most people wouldn't bother to even download so download statistics would plummet.
Most people download the games so they can try them. Most games are awful so they get opened once, tried and then ignored or even deleted.
A few games get tried a few times but then ignored and deleted.
A very few games are really worth it so those ones people pay for.
As to the in-app purchases, I'm not interested in that wallet sucking method of paying. If I like the trial version of the game then I will register it and pay for it. If it is a game that requires little in-app purchases to play, then I delete the game and find another that is a simple buy and play type purchase.