"Donationware", 1 extra spin per game for life if you pay a one off fee (not stackable) and oracle ads are the best ideas IMO.EDIT: Missed the boosters idea. Boosters shouldn't be buyable with electrum IMO as that would reduce the incentive to buy them with cash. Add a foil animation to all rares and nymphs obtained this way please (non-nymph foils would also be available through spins after beating foil users and would be no different to the regulars apart from the awesome shine).If you really want the cards, either pay or get them the regular way. Boosters shouldn't be free. After all, it's not as if they contain new cards.
i wouldnt, or should i say i couldnt. im poor as hell
Extra spins are not a good idea imo. They would completely ruin the rareness of nymphs, and anyone that donated would have on average 2x the normal amount of nymphs.