Just a heads up: you can't earn Bitcoin directly this way. It's true that this can be profitable even with a very modest setup, but a lot of masternode coins are scams. Initial costs are also usually expensive enough that you might as well buy a mining rig setup if it would be profitable for you.
You are right, but at the moment I think it's easier than thinking about building a rig or buy ASIC miner. because of that must requires knowledge in choosing masternode.