Popularity is determined by the no. of owners. Contribution is determined by the time spent at the team. I am curios to know what is the purpose for contribution and if this affects the game play.
What I have noticed is that the more is the contribution the more you will get, if you sell that player.
Ex: If the player doesn't have any contribution, you will sell it at the market value.
If the player have maximum contribution you will get more money than market value.
This stats also determines how expensive the contract will be when you want to renew it.
Related to gate revenue for sure this is affected by the rating of the opponent and by your own squad rating. Also with MyPes inside Facebook, you'll get extra 300k.