I think that post is just junk
User got 5 posts, OK I don't have much more.
I know Alexa is very inaccurate but TGP surfers are dumb and uses IE6 so Alexa penetration is higher so accuracy might be better.
But alexa rank 1,400,000 can't have 2,500 uniques/day. No way. I have one blog with 3-4,000 uniques (about 40% IE6 visitors), and alexa rank from 33-45,000. When my site have 2-3,000 uniques, I have rank about 55,000.
Very suspicious for me, that site with same traffic (as on of my blogs 1 month before) have alexa rank so different. 1,350,000 sites between can't hide in misaccurate alexa with it's toolbar.
That guy is probably try to overprice his sites.
And those earnings looks quite fishy to me. take that he got annualy about 5-6,000 uniques (he say), in reality upon wierd Alexa ranks, he might have 2,000 uniques, 2k uniques on TGP (most fo the traffic is from trades, where visitor is cheated so about 40% of those uniques closes window immediatelly). This means about 1k uniques in reality sees his site. 1k uniuqes on TGP won't earn 300-500$ a month.