Problem is, good game mechanics are very hard to do. But even worse, using such mechanics makes it very easy to accidentally promote wrong behaviour.
For example, score 2 points for sending an email to a prospect, score 5 for calling. 3 emails will give you more points, but any salesman will tell you one call is worth more than 3 emails. So if the "game balance" in your biz app is off, you might thus end up with negative productivity for your users :-)
It's all very interesting though.