UPDATE: My best guess is someone was just banging on the keyboard to make a test ad and KLM are just so close to each other on the keyboard that that's what the URL ended up being.
The sad part is it's probably one of the few ads I've clicked on in my Gmail, so this tactic may be surprisingly effective. :)
We've got a KLM person in the comments who may be able to verify. Kudos to them for following up.
Keep up the good work www.KLM.com!