Google doesn’t equate affiliate links with “paid” text links but they don’t pass any Google juice to linked website either.
Matt said that sites can use affiliate links but Google doesn’t count them as endorsements and than indirectly means that affiliate links don’t flow juice.
Eric Enge: Let’s touch on affiliate programs. You are getting other people to send you traffic, and they put a parameter on the URL. ..If Googlebot sees an affiliate link out there, does it treat that link as an endorsement or an ad?
Matt Cutts: Typically, we want to handle those sorts of links appropriately. A lot of the time, that means that the link is essentially driving people for money, so we usually would not count those as an endorsement. link.