If you’re in the affiliate game, I highly recommend that you take 20-minutes and double-check your links every once in a while.
I finally was able to debug an anomaly in recent site earnings to discover that I was using an invalid affiliate link. A wee mishap that has left me missing out on ~$575 of revenue. Very sour experience indeed, but a valuable learning lesson nevertheless.
Update: The amazing folk at Glispa were able to do some of their own investigating and reassign some missing sales to myself – an amazing service. Special thanks to Brian & Andre.