The time when i joined adsense publisher, its TOS was not hard and tight. Yet! i didn't ever exploited its rules..
But with the increase in fake accounts, invalid clicks, multiple accounts has forced adsense to keep a minimum requirement for approval of the blogs, these are:
- Blog need to be 6 month old.
- With minimum of 20 posts in it.
- Quality maintained contents.
- Not spammy.
- Anyhow it doesn't violate the Adsense TOS.