Thank you alot guys, you have opened my eyes. You said a few things i didn't think of, so thank you.
I think i will try a small experiment. I will pick a random free hosting account, and make 3 free subdomains and build autoblogs. On will have a random url name, not related to the niche, example: "ilikepizzaverymuch.freehostingservice.com" and the niche will be about "football" and build around 1000 autoposts with different posting times, some even from last year so it looks natural for the user. The second blog i will give a name related to its niche and build around 100 posts. Example: "cheapfootballclothing.freehostingservice.com" and the niche will be "football clothing". And the third will be almost same as the second autoblog, it will be related to the second niche, something like: "nikefootballshoes.freehostingservice.com". I will also put a plugin that generates auto sitemap and pings google and also bookmark it, blast a few comments with scrapebox and use the rapid indexer.
As you can think of on a free hosting service there will be alot of other unrelated subdomains, so i guess i will have 3 different results. My goal is to see if i can get these indexed, how fast, which one will work better. Because all this would be on free hosting i want to achieve with each autoblog at least 1$ per month. If i can do that, i would build 500 blogs to make 500$ per month

. Note, i never made any money online so i would be reeeeeeaaaaally happy to make my first dollar.
What do you think? What will be the results of the experiment? And should i do it?
Thank you in advance.