A lot of the interesting stuff I find on the web comes from catching a vague reference in a blog or just plain reading about it in some secondary source. Then, every so often, I actually come across something I think is neat and have not heard of before. The Nextag shopping comparison site is one of those things, or to be more precise, the "Price History" chart in the Nextag product banner is pretty cool.

Above, for example, is a history of the price of my hp scanner (which I really like, BTW.) Clicking through the price chart brings up some more detailed charts of high priced sellers vs. low priced sellers over time and a couple other data graphics. I paid $35 for my hp scanner, which is a pretty good deal compared to a year ago. As might be expected, all the price charts of technology items have a severe downward slope. Except for Apple products, which tend to be flat or slightly sloped. There is something to be said about proprietary products. What that something is depends on whether you want to own the stock or own the ipod.

It might not be the killer marketing gimmick, but I think small things like this make a site interesting, really drive traffic and build a brand. Google and Amazon both do that sort of thing successfully on occasion. For example, Amazon lets you search the full text of books. Google maps out the Thai restaurants you searched for overlaid on a map with text balloons. Both are examples of interesting features that attract people.

Maybe Nextag’s price histories are working, too. It seems they are growing in the opposite direction of the price of most of the stuff on their site.