Paul N, spotted this ColdFusion code in a third-party shopping cart system he'd been tasked with modifying (to make it usable):

 

 

<cfset IDstring = CreateUUID()>

<cfset ThisCustomerID = Left(IDstring, 9) & LSDateFormat(Now(), 'MM-DD-YY')>

 

I guess a UUID was too unique for them - so they've nicely enhanced the chance of collision, while also giving themselves a considerably lower maximum number of unique IDs per day.