Chances are you probably came across a video talking about how you could make MILLIONS mining BTC. If you're trying to mine BTC at this point in time you're going to need electricity that cost less than $0.05 kWh (or almost free...) and new mining equipment. If you plan on using a non-ASIC miner like a CPU or GPU, you're already negative $$$. However if you would still like to see what's most profitable with the equipment you wish to purchase or already have visit: whattomine.com. This will give you an idea of what to expect.