Best PPC for Tech?

i applied for google adsense on my tech site but rejected i think my site is just new 1 month maybe the reason, now i am using adnow and bidvertiser ad and getting very very low cpc and cpm, really dishearted . suggest me other good ads who gives better ppc then adnow and bidvertiser.
Also suggest me when again i can apply for google adsense, i have a good traffic

SEO student :p