i'm using channel by ads. example if my site any 3 ads, I give name on link unit, middle center ads and left ads there is effective to track my adsense or not?
That's what I'm doing for my sites. Custom channels are great to analyze to see which ad placements do the best over a given amount of time.
Channells are a way to know which of your website(s) or webpage(s) are performing more than the other. Suppose, you have a website in which you place articles about Dogs and Cats. Now while putting adsense ads in these webpages, how would you know which of your webpage, i.e, either about Cats or Dogs is fetching you more money than the other? Enter Channells. With Channell feature, you would create two Custom Channells for Cats and Dogs. While generating the Ad Code, there is an option to associate a chanell with that code. Thus you can associate different channells (Cats & Dogs in this case) to ad code and place this code in appropriate pages. This way you can see how much impressions/clicks each webpage(s) (Cats & Dogs in this case) are getting and try to optimize webpages specifically.