This is the search giants first foray into competitive research, and comparisons are being drawn to Alexa and Quantacast.
Barry Schwartz points out a good use for the new tool at SearchEngineLand.com:
Now, if you think like a link builder – you can use this tool to find sites that are within your “neighborhood” or industry. So if I want to find link partners for the Search Engine Roundtable, I enter in seroundtable.com, look at the related sites and ask all of them for links. Then I go to all of those sites and see who is related to them. You can, theoretically, keep expanding that list, as far is it makes sense.
Some think that the tool is a misuse of Google’s data, sighting the ability for anyone to gain a new competitive edge. This of course was possible before, when for a fee you could snoop out information on your competitors via Hitwise and Comscore.
I see some great applications for the tool in terms of link building and competitive analysis on the cheap. Its competitive reporting at the best price point, free.