Need Help! how to increase the Scrapebox harvester success rate?

Why my scrapebox harvester success rate is very poor,especially harvest form google.
Sometimes I test 50 keywords only harvested less 100 results,and most of keyword can't been successfully harvested
For every time before start harvest I always harvest fresh proxies,and test all of them,left only which connection speed fast
Or I harvest without use proxies,most of time will return error :IP blocked
So how to work out this problem!
thanks !

Use private proxies if you can - otherwise you have to search/filter pretty hard for effective public ones but it is possible.

proxies dude...
buy some private proxies and rotate them

Thanks guys but yourprivateproxy is too expensive
Is there have any cheaper one

Private proxies is a option but the main thing is that you will not get very good result. You can try to find the result by doing it with new keywords.
thanks