It also assumes that there's no limit on URL space that bit.ly provide. Tomorrow they could just max out the "long_url" field or whatever they call it to just accept 1500 chars or something
"Storing a document in a URL is nifty, but not terribly
practical. Hashify uses the [bit.ly API][4] to shorten
URLs from as many as 30,000 characters to just 20 or so.
In essence, bit.ly acts as a document store!"
While the HTTP specification does not define an upper limit
on the length of a URL that a user agent should accept,
bit.ly imposes a 2048-character limit.