Evaluating the performance in sales team?

I think your thinking is in the right direction, since gamification hasnt been applied much to sales yet. I have introduced a loyalty/ gamified program to endorse every activity (call, meeting, proposal)and showcase how active people are correlated to their revenue/ target. Awarding activities, besides actual revenue in a loyalty dashboard, can activate the intrinsical motivation of your sales team. P.s. ping me if you have any additional questions!