For hyopthetical example, I search for "blue widgets" and see an ad for this money making opportunity.
Now, I've tried advertising some products in other complimentary niches but thanks to Google's "relevancy" software the minimum bid is always around $5.
So today just out of curiosity I duplicated one of these ads- title, link, text- everything- just to see what sort of bid Google would give me.
It was $10 per click!
So how are these people getting around this?
Not necessarily.
Easy enough to check. Set your user-agent to the appropriate spider. (Google has a different spider for Adwords.) The Firefox "User Agent Switcher" extension would come in handy. Visit the site with your user-agent set to make you look like the Google spider.
If you find that they are showing widgets to the spider, but wadgets to everyone else, report them.