Term: "rubber ball"
Search Network: 500 impressions per day
Content Network: 1,500 impressions per day
Term: "viagra"
Search Network: 5,000 impressions per day
Content Network: 500,000 impressions per day
Term: "mud pile removal"
Search Network: 5 impressions per day
Content Network: 0 impressions per day
The Content Network is composed of individual websites that run Google ads. Depending on the nature of the terms, you may get a lot more impressions or almost no more impressions. Remember, too, that on the Content Network, your ad is competing with the site it's showing on, so your CTR may be very low on the Content Network even as you spend more for the increase in overall clicks.
IMHO, try it, but don't use a lot of money. You will be able to tell which end of the spectrum your terms are on very quickly, usually within one day.
In one of my main areas of operation we get 300 times more traffic from the search network, the content network just does not have Adsense publishers operating there (the CTR is decent though on the sites that are there and the traffic is good).
If you find yourself in an area where you can't attract content traffic why not contact a few site owners, as hard as it may be to believe, there are many people out there that run sites for the love of it rather than for financial gain. Some people are happy to do deals that simply cover their running costs! It's a good amount to talk about when talking to a site that has no advertising, their partner may be miffed that the site takes up time and money. You can sort the money bit ;)
