Like a lot of other affiliate aggregators that specialize in software, Clickbank is known for having lots of 'junk' products with descriptions that are stereotypical of SPAM and scams.
Don't be afraid to ask a review copy from the vendor, and filter out the good & the bad yourself. Here is a tip: http://www.dubturbo.com/affiliates.html Great product that is defiantly worth checking out. I made a total of 49 sales, and only had 3 refunds.