purplecape - 8:22 pm on Jul 2, 2008 (gmt 0)

A site that has content that consists only of ads (and I've seen plenty of those)--clearly MFA.

A site that has substandard content, and lots of ads--almost certainly MFA.

A site that has good content, and ads that take up no more than 1/3 of the available space--almost certainly not MFA.

There's definitely a grey area, and as we can't know people's motives, I tend to give people the benefit of the doubt, but even then I see a lot of sites that I consider to be MFATTM (Made for Adsense to the Max).