As a property owner, I figure out the market value of homes I have for rent by looking at craigslist and “surveying” the current asking prices over the last several days based on comparable listings.
Seems like a piece of software that did that would be worth a few dollars per month in ad revenue.
Dude, this is an excellent idea! And it can be extended to anything really… hard drives, couches, etc.
I once had an idea about building such a tool on top of eBay. It would measure price elasticity of a certain product (or products with a certain feature set) and tell the seller what a good price is, and tell the buyer which items/auctions are a bargain or a rip off.
It’s a lot easier to build when you’ve got structured data to work with(as some of ebay’s listings now do), but would be a bit harder on craigslist since there is no structure to the data there.