How come always fail to harvest Proxy?

i try to harvest proxy by using SB recently but the rate is terrible low, almost 0.1% success to harvest proxy list? how come..

I'm not a SB user but I'm an experienced proxy scraper. Sounds like:

1) The places you're scraping from suck
2) You're scraping a lot of non-anonymous proxies (eg. transparent) along with your anon proxies and it's distorting your numbers.
3) You're setting the timeout too low - remember lots of peas are very slow.
4) I would say around 10% of anon proxies listed on proxy sites actually turn out to be both working and anonymous.