I'm thinking of starting a new referral (a.k.a. lead generation) service and I was wondering if anyone has experience with any "referral" plugins for Wordpress?

I'd like it to b as simple as possible for the site visitor, let the business know that it is a referral from my site, and a log is kept (or I'm sent an email also) for each lead sent out to the business.

I see quite a few on the Wordpress.org site and several have 4.5-5 star reviews.

Suggestions?