Interesting, I've been doing just that for the last couple of years. It's been a mix of partial successes and total failures, mostly failures. I didn't want to go the 'mfa' route for obvious reasons, so I try to make these sites in to something that actually is useful, and that have a sense of community about them. Here is a breakdown of what you can make this way in a month based on adsense alone after several years…
I agree completely, $1 a day times 400 sites is simply not feasible. This article is terrible advice, the kind that will probably lead you to failure. I have a fairly successful affiliate marketing business (I make more than I would if I had a day job), and it seems like every day I talk to people who are taking this approach and making $1-$2 a day. The article's logic is flawed- if it were that easy to make projects…
My freshman year of college our rowing coach took us out to the salmon dam on the edge of the lake. He turned to the boat and asked, "How many times do you guys think the salmon try to jump over the dam before they give up?" I can't remember everyone's guesses, but the punchline was basically "They keep trying until either they make it or they fucking die."
This seems to be the ideal strategy for startups. The person who wins isn't the one with the biggest shovel or the one who digs the most holes, it's the person with enough discipline to keep digging in one place with the shovel they have.