Looking more and more like eBay (or Amazon) everyday, Google Base is apparently testing a ratings system for buyers (click image for better look):

One major hurdle for Google to overcome with job listings is the obvious amount of spam that a user may have to weed through while browsing listings.
A ratings system could be one deterrent Google could implement to police job listings behaving badly.
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Joel Cheesman - who has written 1279 posts on Cheezhead.
One of the most widely-read bloggers on emerging recruitment issues in the world. Accomplishments include being named Recruiting.com’s Best Technology Recruitment Blog and Best Recruiting Blog. Joel's been featured in Fast Company magazine, BusinessWeek Magazine, Resumes for Dummies, U.S. News & World Report, The Wall Street Journal and more. Plug into Joel via Twitter, MySpace, Facebook, iTunes, YouTube or Flickr.
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March 10th, 2006 at 6:59 am
this will also oblige companys to answer to their applicants unless they want bad ratings … it’s not just about the “item” advertised on googlebase, it’s about the whole company’s “customer services” … IMHO