I have been using the site - Pennyful for quite some time now. I can say that they have brought innovativeness to the cashback industry. The concept of tool bar is mind blowing.
The best feature is there is no minimum limit for cash withdrawal/donation. All other sites are saying that there should be minimum Rs.250/- for withdrawal.
Pennyful allows even Rs.50/- for redemption.
There is no extra hardwork to earn the cash back, just follow the simple instructions given in the site.
I give thumbs up for the entire crew behind Pennyful for their success.
All the very best.