hostname.com/business.txt is wrong.

You are supposed to use the /.well-known/ subfolder.

http://tools.ietf.org/html/rfc5785

If you plan to implement a "standard" please try to review the RFCs that have covered this ground before. There's probably already a standard which may fit. If not, there's probably one that's close you could propose a change to. And if you're trying something genuinely new, you'll at least be on the right foundation.