Unless I know of your earlier games or I've had it recommended to me either personally or if you're lucky enough to be chosen for the Editor's Pick on the App S

Unless I know of your earlier games or I've had it recommended to me either personally or if you're lucky enough to be chosen for the Editor's Pick on the App Store i'm not very likely to pay for a game or apps in general. I think level packs are pretty much a match made in heaven for puzzle type games, as are selling credits for hints. Be sure to include at one or a few hours of gameplay for free, that seems like a nice balance. Updating with new level packs every now and then (both paid and free) is a good way to keep people excited and get additional income from people who really enjoy the game. Selling additional color/texture themes might also be a way to increase sales.