I’ve never really heard a sound argument for letting affiliates bid against your brand within pay per click advertising. Even in a closed, carefully selected way. Whether you let one affiliate do it or 100, you are cutting off your own foot.

Think of it this way: You let Affiliate A bid against your brand. No. 1, by doing so you are adding competition to the one area you have an edge – brand recognition. If you’re used to paying low on click through you will now likely have to pay more for each click because your affiliates will now be competing against you for the same keywords.

Aside from the increased cost in clicks, you’ll also be paying out more in commissions when your affiliates start closing more sales from those ads. Just because you are making more sales than you did last week, or last month, doesn’t justify your decision. What matters is that you likely would have closed those sales yourself based on two facts and one assumption:

• FACT: You were sole bidder for your brand
• FACT: The searcher queried and would have seen your PPC ad all alone in the SERP
• ASSUMPTION: Your ad and landing page were equal in quality and closing technique as your affiliate

Note that my argument is contingent on you being as good at sales as your affiliate. If that’s not true and you know it’s not true then you might let your affiliate bid against your brand. But for that to be the case you should be confident that you are losing sales yourself by advertising. Nevertheless, you could do just as well by testing new pay per click ads and landing pages and increasing your conversions. Your affiliates have other means of reaching their audiences.