I would either concentrate on one or two or generate a million of self updating blogs and just let them be. PS: Why do you want PR? Do you realise you need traffic to make money from Adsense and not PR PPS: If you do decided to go ahead keep us updated. Hope it works out for you.
Go for it partner. I had a friend try something like that about a year ago. He lasted about a week before burning out. You're better off with niche sites. Better yet, focus on only a few sites and park the rest. I believe the cost in money and time will greatly outweigh the return on the whole blog thing.
Hello all, Thank you for all your honst suggestions,both opponent and assentient,you just let me know that it is not easy and make things clear. What you did will help me to avoid the wrong directions and save my time if i follow that wrong directions.As i have said that i have started 25 untill now,so i will focus on that 25 blogs,5/25 will be focused on the quality,for the rest—300 blogs,let me just think about if someone would like to take them as adoption(or something like that),or any other ways to market them which have not came up to my mind yet. Thank you for all your suggestions.I will keep this thread updated.