Wait what? $1,500 for 20,000 plays? If the average song is 4 minutes long[1] that's 55 days of continuous music. So, a radio station that played non-stop music, 24/7 for a year is going to pay just under $10,000 total in royalties.. for a year.
That's pretty amazing, but I guess it's a matter of supply and demand: there's an awful lot of music (and a lot of it is awful).
1. http://a-candle-in-the-dark.blogspot.co.nz/2010/02/song-leng...