Does anyone have a link/website to the articles which state

That 90% of Ebay merchandise is fake. I am trying to show it to someone but I'm having trouble with the search function. Thank you.

The estimate varies by manufacturer, and only a few have released figures. Here's what Tiffany and Louis Vuitton say:
Tiffany:
http://www.msnbc.msn.com/id/6030048/

LV:
http://www.pocket-lint.co.uk/news/news.phtml/4844/5868/ebay-vuitton-dior-lawsuit-counterfeit.phtml

For certain, at least 90 percent of Coach wallets and keychains sold on Ebay are also fake.
 
Excellent articles, but note to the OP that this 90% pertains to only those brands, not 90% of ALL merchandise sold on eBay. (No, I don't work for eBay!)
 
Excellent articles, but note to the OP that this 90% pertains to only those brands, not 90% of ALL merchandise sold on eBay. (No, I don't work for eBay!)

Of course not, but it's certain that anything that can be faked, will be. Not just obvious things like purses, dvds and celebrity autographs, but almost all electronics, computer software, clothing, sporting goods, etc (fake golf clubs are a big problem on Ebay). Even inexpensive items like regular LeSportsac purses and Weekenders are faked although more of the fakes are sold on Ebay's far East and Aussie sites than here, but some still make it through to the US.

You could take any brand of popular clothing, from Abercrombie & Fitch to Ralph Lauren and Google the name and the word "fake" or "replica" and find dozens if not hundreds of sites selling fakes of that brand. The only reason the "percentage of fakes" estimates aren't higher is that most buyers have no idea those brands are even faked. When their $105 retail price jeans that they only paid $29 dollars for fall apart, they just shrug and figure it was a "second" or that the quality isn't what it used to be.

I think if every major manufacturer represented on Ebay bought a sampling of their brand's items and checked them for authenticity, they'd be appalled. And so would Ebay buyers if the figures were ever released. It's like Coach keychains - because they aren't a $400 purse no one expects them to be faked, but they are. And that 90-95 percent fake number I gave is based in my own counts of the keychains I've checked and reported.

And the situation will keep geting worse because the sellers of cheaply-priced fakes keep driving out the sellers of genuine merchandise who can't compete with the fakes on price.