Originally Posted by
Diplomatico
That rule is in place to deter indigent backpackers on visa runs, basically.
And, from what I've been told, people from neighboring countries who travel out and into Thailand every thirty days to get new visas instead of getting the correct, longterm visa. I knew a couple people who would take a bus from Bangkok to the border every month to do this, but have since moved back to Laos. FWIU multiple visas from land crossings can trigger a cash check.