I have a friend who works in a library and has a primitive blog documenting the things she learns every day. I learn things from my customers, and think I'll occasionally document some of those here.
Today I learned why counter checks are called "counter" checks:
A customer was telling me how her grandfather owned the local feedstore when she was a kid. There were only two banks in town at the time, and the feedstore kept blank checks on the counter from each bank. When someone wanted to pay out of their bank account, they would grab a check from the appropriate institution and write a check. When my customer's grandfather deposited these counter checks, the banks would look up the account numbers and dock the accounts.
Here's the kicker: When people started getting personalized checks, my customer's grandfather preferred not to take them. His experience was that a lot of personalized checks were stolen, and counter checks were more reliable.