Preordered ASICs are landing in the hands of the customers, and difficulty is rising greatly
what about usb which using for mining is this ok and in reach of all or its also very hard to earn
The consensus seems to be that block erupter USBs are not profitable. They are more of a novelty item. You can tell a lot by the price at various times. It was introduced at 2BTC and the price fell all the way to the current 0.10 BTC.
edit: You may want to refer to this graph. It shows how difficulty increased over time:
http://mining.thegenesisblock.com/
thanks its very useful now I want to give try to this mining once and now will do with GPU and LTC as I have this set up I send you message thanks