I think that by now we are all probably aware of Wikipedia, where the entries to a dictionary online are made by the public, and added to or corrected by the public as well.
Someone just had a great idea that runs almost the same way. Shopwiki.com scans the internet and gathers information about products without the advertisers having to do anything other than have their products listed on a webpage. Then the details are entered into a directory at Shopwiki.com making for an overall amount of products that far exceeds any listed by regular retail websites.
There is a good search feature, and the items are listed by category, anyway. For instance, say you are wanting to compare prices on
Playstation then you would click on video games on the homepage, and then the Sony Playstation, to look at the specifications, then just click on search at the top window and as the name is already in there, it will take you to the listings of everything that is Playstation related, including games, and the actual game console unit itself and the suppliers offering it as well as the prices.
A wealth of information. Or, from the specification page you can get more details about any of the linked words, such as Blu-ray player
Blu-ray player there! See how easy it is to find stuff for great comparison shopping? Lets, just for giggles, try another link, say, Xbox 360 and we end up with the sales listings for
Xbox 360 then we can go even further, such as hovering our mouse over, say, the Xbox360 Thermostatic Cooling System, we get a list of suppliers and prices for that particular product.
Right now Shopwiki claim to list "245,398,189 products from every store", and I see no reason why, with the system that they have to obtain listings, it shouldn't be double that figure by the end of the year, or even sooner.