Just a thought.. maybe players who make cards which are accepted into the game should get a copy (or 2) of the card

Sure, it only sounds normal and I agree. However it has some drawbacks and the biggest one is that it creates an expectation to earn something out of it and this is something that can potentially harm the purpose of suggestions.

Suggestions should aim in making the game better for all which in turn will make the game bigger. The bigger the game, the better for all as this will mean more competitive gameplay with more friends and enemies. More competitive gameplay can mean more entertainment as this is also the purpose of the game.

Sure there are exceptions and there are many people that want to be first no matter what and this gets more difficult if the game is big. Still, every place then has a bigger meaning so in the end, if you are enjoying the game, you will settle down with a place outside top 10

Yeah I guess knowing you helped out is reward enough