Earlier quoted context omitted.
From my experience, 500,000 pageviews a month will turn a decent profit. Absolute minimum seems to be 100,000 a month, which is extremely easy to obtain these days.
OK - I'll bite :) Could you qualify why you think it is easy to get 100,000 pageviews a month? I am intrigued.
I consider 100,000 pageviews a month easy because I can achieve that number organically (without paying for traffic) within a few months.
My niche is probably a bit easier than some others, though.
I also consider it easy in comparison to the fact that it took me 2 1/2 years to get to 600,000 a month when I first started. I could probably do 600,000 organically in half the time now.