What happened?  Chances are, there’s a sales page leak or other affiliate commission leak somewhere in the sales process.  If you’re dealing with a shady vendor, it might even be intentional.

Here’s what to watch out for:

Multiple payment options on the sales page.  If the affiliate program is through Clickbank.com but there’s a 2checkout.com or Google Checkout payment button on the page, you’ll lose your commission if the buyer chooses that option over the Clickbank button. Likewise, you’ll likely lose commissions if there are other ordering options such as fax, mail or phone.

Google AdSense on the sales page.  That’s right, some vendors actually put Google AdSense or other ads on their sales page. That’s just one more thing that distracts the prospect and takes him away from the page.

Affiliate program links on the sales page.  If the vendor is advertising the affiliate program right on the sales page, you might have some prospects using their own affiliate links rather than yours. End result: You lose a commission.

Other unneeded links on the sales page.  Generally you’ll find some links on the sales page are necessary, such as a contact link, a terms or service link and/or a privacy link. But if there are links that lead prospects off to the vendor’s blog or elsewhere, some prospects will click away – and you’ll lose a commission.

A sneaky vendor who steals commissions.  This one covers a wide variety of sneaky tactics vendors use (often deliberately) to swipe your commission. For example:

Distracting prospects. Here’s how it works: They use a squeeze page to collect names and email addresses BEFORE the prospect sees the sales page. Generally this isn’t a bad thing, because the vendor helps close the sale via his autoresponder and you get the commission. However, some vendors use their own affiliate link when they email the list. Or, they use the list to sell totally unrelated items right away (meaning they didn’t even attempt to close the sale on the main product, not even in the first email they send).

Yes, a vendor is free to use his list as he pleases, but do note that if he’s promoting other products in the very first email, then he’s actually distracting your prospect from the sales page and sending him to a totally different sales page. No commission for you.

Faulty tracking. Test this for yourself. Perhaps have a couple of friends purchase the product and see if you get credit.

Phantom refunds. Here the vendor records refunds that never happened. That way he keeps the full commission. (Tricks like this don’t work if you’re using Clickbank.com.)

These are NOT the only possible means of you losing a commission, but they give you a good place to start when you’re researching any new affiliate opportunity.