You've read the TOS, of course?

AFAIK, there's no rule against most of your visitors coming from one source, but you may find that your earnings won't be as high as they would be if your traffic came from a wide range of sites.

It's worth revisiting why exists exists in the first place and why it is any good.

AdSense is designed for content sites. It targets ads to the content of a given page, on the basis of 2 assumptions:

1. The idea that visitors are viewing the page to due interest in that content, the actual words on the page. They have usually either navigated to that page from an internal link due to some kind of interest in the content, or arrived from a search engine in which case it's again reasonable to assume that the page content is relevant to the users current interests or needs.

2. People seeking factual/textual content are more likely to be in a buying or need-satisfying mode. That's as compared to people killing time by looking at pictures, socializing, or playing games.

Orkut and MySpace type traffic is probably going to be a very poor fit for contextual advertising on both of these counts -- in fact Yahoo is rumored to have banned sites from its program due to reliance on MySpace traffic. You can expect a very low CTR and lower-than average earnings per click as well.

The same applies to picture galleries, which several people have started threads about lately. Google doesn't normally kick publishers out for being a poor fit, but they can expect to earn much less than content-centered websites.

jomaxx has made my point much better and in more detail....

>>>The same applies to picture galleries, which several people have started threads about lately. Google doesn't normally kick publishers out for being a poor fit, but they can expect to earn much less than content-centered websites.<<<

how are picture galleries relevant to a thread about orkut?

photos are most definitely content, and if you don't know how to monitize picture galleries, they can also be used for driving qualified traffic to textual pages.

adsense can be a great fit for all kinds of media and all kinds of traffic, but it could require experimentation, and possibly some filtering, to optimize the r.o.i.

how are picture galleries relevant to a thread about orkut?

Why is it necessary to be so combative? I said EXACTLY why; I just didn't want to have to make the same basic post in multiple threads.

I agree that photo galleries can be targeted to a subject area (usually are not, but can be). However you've still got the problem that people looking through a picture gallery are not in an ad-clicking mode or a buying mode. That's especially true if the images are what's driving the traffic, e.g. from Google Images.

>>>Why is it necessary to be so combative?<<<

why are you so sensitive? i don't have an orkut account, so i'm asking why you'd bring up picture galleries in a thread about orkut... i thought it was a social networking site, not an image site.

beyond that, i have figured out how to monitize picture galleries, including google image search, so i don't agree with any of your generalizations there.