Just sold my first beat too today.
I did it by searching on twitter for people who want beats. I do this a lot actually, i've had 1 answer last week but no follow up, today, the artist responded within 2 hours and it was done.
I am so excited to hear someone drop fire on MY BEAT ahahahahahahaha my god, i want more i want more i want more i wanna sell 1 million dollar of material coming out of my brain. This literally is just air moving around a room.
Music is some awesome i swear ...
Also i recommend this site sendbeatsto.com . I have been sending beats for a couple of years (i think) on this site and i've never gotten an answer but i don't care, feels good that someone has my beats on his mail/computer.