Ask HN: Chances of making Mulah from a startup!

What are the chances of making a decent amount of money from a startup (say >$150k pa pre tax)? I know that it is not something to do if you are just after the money - as there are surely easier paths there - but I am still interested. And regarding the fact that often it comes in a big lump on exit, how much would a successful startup like Dropbox be pulling in (in profit for the founders) a year?