Most of the eBay sales are little piddly amounts, but I've not done badly with them. Things that I've found most useful:
1.) Try to get people who are looking for products, not for auctions -- that is, people who may not have eBay accounts already. At $25 each for new signups, a new signup is worth far more than the $0.50 commission on whatever $10 tchotchke they bought.
2.) You might get lucky. I got one $1397.82 commission from eBay once. My only guess is that someone followed one of my affiliate links, signed up for a new account, and proceeded to buy a goddamn house.