I dont think that would be an issue as long as you dont ask them to click the ads as well. make sure to read over thr TOS to make sure.
I don't think any affiliate program would have a problem with this. Even adsense. I could be wrong, I however am willing to bet money on it. That's the entire point of the referral link, it doesn't matter if the reason they click it comes from word of mouth, or simple interest on your page IMO.. Yes check TOS, I however would be guilty of this as well