I think you mean the difference between Bitcoin Mining Contract and Altcoin Mining Contract.

Bitcoin Mining Contract is stated in Terahash and is based on SHA56 Algorythm with this contract you mine directly bitcoins. Supporting the Bitcoin Network with your mining power.

And with Altcoin mining contract stated in Megahash you mine altcoins and genesis mining is changing this coins in bitcoins on request or you can payout dogecoin at example to your doge wallet. This mining is based on scrypt Algo.

Which one of these two is more effectiv you have to decide for yourself.

In my experience altcoin mining is highly volatil huge ups and downs. Bitcoin mining is more stable.

I hope i could help a bit i would appreciate if you use my promo code.

If you have any further questions dont hesitate to ask.

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