There are only two formulas that have been proven to be really successful for beatmakers..
1) Find a local rapper that you believe in and he/she believes in your sound, and grind together until you make it to the top...Work exclusive with that rapper and his camp, because you never know which beat is actually going to blow up...
Example of this formula are people like Dr Dre and NWA, Dr Dre and the Dogg Pound, Young Chop and GBE/OTF, Lex Luger and Waka Flocka and many more...
2) Find a producer with an established reputation and work under them...You will lose a lot of money, because they will take credit for your work...Examples are The Neptunes, Kanye West, Alchemist and many more...
Most of the top producers in hip hop (who have been consistent) cam from these two formulas...
And it's not only restricted to hip hop...If you listen to the stories of the legendary musicians, they all came up around other legends or other people who had their foot in the door...
Selling beats on the internet is not going to get it done...
You need to be go getter and move to a place were people are doing things and making things happen...