I am using a large number of affiliate programs to market products for a client's web site (which must remain nameless). We've had great success, but just realized that we may be paying multiple commissions for a given order if the user has come to our site multiple times through different affiliate links.
For clarity, say user X comes to our site from a Google Affiliate network link, browses around, then leaves. Then they do another search somewhere else and end up at the same page from a Commission Junction link and that sets another cookie. When the user checks out, they will have a tracking pixel for both sites in their order confirmation page and we will end up paying out a commission to both affiliate programs.
The more I think about it the more complicated it gets. I realize that some of this might depend on the individual affiliate program conventions, the contractual obligations we have with the affiliate, the particular implementation, etc. -- but I'm wondering if there is a standard solution for this problem in general? Should I add some logic to my app to figure out which cookies to honor and only count the commission for the most recent affiliate referral? In some cases incoming affiliate links might be product specific so in those cases we could probably track whether the customer purchased the particular product from the particular affiliate referral and do some logic to enforce those rules, but suppose they got to the exact same product landing page from two different referral programs and then placed an order? Should they really both get credit for the referral or just the most recent one?
I'd appreciate any thoughts on this from experienced affiliate marketers in particular.