>>1368968F shares are safe investments. You will definitely see a positive return over a relatively short period of time. However, the profitability window is very limited.
Investing in M is risky. Many times you will get no revenue at all; what's more is that these shares are more costly to begin with. So why bother with M? If you're buying from a company that you've really done your homework on, returns are gonna be great. These tend to be lifetime income generators as well. In the case that your investment doesn't pay off, BoDs of these companies tend to be very liberal with the rules, and the company usually has time to change its habits.