There are 3 of us they have done or are doing this to right now, Bare Rose Garage had the same problem at 452 subs and another channel is having the same trouble at 552 subs something about the 2
Found the interview. I thought its was on Freakonomics but it's with Dave Davies who also is pretty good, unlike Freshair's main host who makes me nautious.
edit: I didn't know the link would embedd an audio.
If you click on the title, you can read the transcript.