The most intriguing part of the story is this one sentence:

“Notwithstanding that eBay attracts mostly buyers and not a whole host of other people looking for knowledge or to be entertained, Google and Yahoo attract a larger audience than eBay.”

In eBay's favor: eBay loyalists have a different mindset from search engine users. The Internet was originally created to inform and that is what's on the mind of the majority of SE users. However, when Jane Smith goes to eBay, she knows very well that she isn't going to find information.

In addition, Jane 'targets' herself. Targeting is a marketing term for making the message fit the customer. On eBay, Jane isn't going to be looking in the jewelry categories if she isn't interested in jewelry. So, for eBay sellers, their buyers obligingly target themselves.

Against eBay: as the article states, Google and Yahoo have more customers to offer. A lot more. And one other very important consideration is that sellers can charge more money off eBay than they can on the auction site. The mindset of visitors is that of bargain hunters. They aren't going to pay retail prices on eBay for consumer items that are available elsewhere.

The easy growth days of eBay are most likely over, and we now have an interesting Clash Of The Titans shaping up. Most likely sellers will profit from this. I'll drink to that!