Would google penalize you if you have affiliate links leading to relevant products? What about the no follow tag? is there anything good about using this with affiliate links? is it a bad thing? Can affiliate links get good rankings on search engines ? Remember I'm linking to relevant affiliate products
If you have a web site with product pages on it and then you have affiliates who send traffic to you product pages in hopes that they will convert into sales (and therefore commissions), to my knowledge Google does not penalize sites for this. This is MUCH different than buying links from other sites. Google typically doesn't penalize URLs because of their inbound links anyway because any competitor could then get you penalized by paying a spammer to spam a bunch of troublesome links pointing at your site and then report you. Worse case, the affiliate links will be devalued and not get counted. It's VERY unlikely that would EVER lead to any type of penalty... On the contrary, the links may get counted so... Since most affiliate links to your pages will likely come in with query string parameters like http://www.example.com/some-product-page.html?aid=234282 and because each unique URL (including the query string parameters is seen as a different URL or Page) I would suggest in the header of your product page that you add a <link rel="canonical" href="http://www.example.com/some-product-page.html">. This way regardless of whether a link to your product page includes a querystring, all links will be applied to the canonical URL.