Implementing an affiliate program - risks?

Hi all
I am implementing an affiliate program for people to sell my products. It is all based on affiliates being assigned a url like so: mydomain.com/affiliate_userid and then they can use the url to put on their facebook page, twitter account, blog or even email. When someone clicks on the link then the system registers it as a sale and pays them.

For the sake of argument lets’s say that the affiliate program is so good that 5,000 people sign up and all have blogs where they put the links. Is google going to think I am spamming? Should I have the affiliate code hidden using js? Or maybe a completely different site? I am also worried that I am going to appear in the serps for the keywor “affiliate program” not my product keyword. What do you suggest? Thank you!

Make they hyperlinks nofollow, that will eliminate any spamming/link buying fears.

Make all the mydomain.com/affiliate_userid webpages noindex - you wouldn’t want anyone arriving on these webpages from a SERP anyway.

Thanks so then I’ll just 301 redirect them to my landing page from mydomain.com/affiliateid to my landing page? My landing is my main index page

If you were to have 5000 affiliates and you will be caught spamming by google ( where did you get this idea ) … you know what you will do? You will be counting money from you yacht and would give to much care about what Google says!
Also you can use redirect links with no follow on them.