If you want to follow any CALLS given by someone, my advice is that you (yourself) follow the calls with mock trading for sometime, and, assess the same. Only then you would know the quality of the calls and whether they are achievable. This would also help you to form your strategy with regard to allocation for each scrip. Atleast bare minimum that you would want is, one who is maintaining his calls till exit. Dont go by we gave you a buy of Nifty Futures at 4423, and, is now xxxx, etc., These promos select only the best call given by them. You need to do your homework even in assessing these calls. There was a guy called stockwhizo (long back during KP days), and, his calls were excellent and unbelievably good, trust me, he was too good to be true, though boasting himself. He is not to be found after one disasterous set of calls. Anyone know of him?
Sharekhan was giving Eagle Eye, where they maintain their calls, and, it appears to be good. You can check out their report (if they have it now).