It was basically a USB or PS/2 powered bar code scanner that was vaguely shaped like a cat. The company would send you one for free. (In exchange you would need to provide demographics and they would collect usage data.)
Magazines like Wired would have these special bar codes that were like UPCs but with diagonal lines that looked like this:

You would scan these codes and it would take you to a web site with more information about the product. That way you wouldn’t need to worry about URLs…I guess? I mean it’s not like we didn’t have web search or online shopping back then.
I had a CueCat and I basically used it as a cheap barcode reader for conventional bar codes. It then lived in a drawer after the novelty wore off. I don’t know what happened to it after that.
The whole thing was a pretty big failure that was a solution in search of a problem and it never really took off.
Hey, don’t shit on one of my TV guilty pleasures.