Search Total VS Content Total on Adwords

I see on google adword that you can opt for your ad to appear on sites that are similar to what you're sellling, and that would be under the "content total".

My question is, does google charge you if your add appear on these sites, or when someone clicks on them?.

Thanks

 

You're charged when the ads are clicked.

If you want to pay for impressions (CPM) set up a site targeted campaign.

 

Beware of using content. My experience is not good. You risk a much greater exposure to click fraud.

 

Just like any other form of marketing, you need to test everything to figure out what works for your business.