Hi. I use 20 semi-private proxies from http://cheapprivateproxies.org/
and I don't know why, but it makes my LPM lower when I use proxies for all settings.. (I'm ranking youtube videos) My LPM is below 1 for not that spammy engines like articles, videos, web 2.0, basically everything besides trackbacks and exploits, blog comments and guest book. I set up 120 threads. And when I enable proxies only for Search Engines, it makes my LPM ~4. Without any proxies it's between 1 and 2. Same with spammy links, with proxies on everything I have 5 LPM, with only on Search Engines its 20-30 LPM. The proxies all up, and after testing they have speed between 0,6 and 1,2. I was running theese campaigns on my PC - 4 GB RAM, 2.6 GHz quad core.
And besides that, I'm planning to buy a VPS. Is 2 GB ram and 2.0 GHz quad core enough for 15+ campaigns at once 24/7? However, it's pointless if I'm gonna get 0.5 LPM because of theese proxies..