With the exception of Ul'dah and Gridanaia, on Excalibur, the bots tend to be one every hour or so until the free week is up (which ends in 3 days.) During regular subscription time, hours would go by without seeing any tell spam. This is of course, because there is only a very short window to create characters on Excalibur.

And as I said SE could improve upon this by making characters have a cooldown on deletion... but it would then waste further server capacity as they would then never log off.