Guerilla allergy marketing - effective?

  1-800-4-ZYRTEC 
  Originally uploaded by Pete Kim.

Seen on the streets of Boston.  Amanda mentioned this on Adrants.  Wonder if the pulled tab was a prospect or PR?

Cheap.  Effective?

Calling the number sends you to what's essentially a 40-second radio commercial.  "For more information visit zyrtec.com."

At least it's different, I guess.  Let me wait two hours and see if I feel anything.