I had a quick look at Bitcoin recently. I came to the conclusion that the ship has sailed. I considered the possibility of mining bitcoin. In the past bitcoins were fairly easy to mine, so if you earned a stash, then today it would be worth a small fortune. But these days the cost of mining is prohibitively expensive, requiring heavy duty hardware, costing $$$. So the cost of entry to mining is high, and you may not see a good return (if at all) for some considerable time.
I think a lot of people these days buy/sell Bitcoin, just like stocks and shares. I don't really know how viable that is and what kind of returns you would get, but I imagine you have to invest big to see a decent return on investment.