Just a warning to you all, it seems these jokers are hitting Austin now.

They work by pulling owner's names from the tax rolls, particularly new and recent home purchases, then leaving door tags stating they have a delivery for you. The tags will have the date and your name, followed by:
"Sorry We Missed You
Please call to reschedule
San Antonio Metro:
210-515-5276
Austin Metro
512-942-6211
Confirmation # (6 to 8 digit number)
Thank You
Metro Delivery - Quick, Secure, Reliable"

The tags look mostly legit, but obviously they are not. The "delivery" is a packet of junk coupons. When you call the number, they'll even offer to deliver said coupons via email. (which will just be a link to a scam coupon site, followed by selling your email address to other marketers)

The real purpose of this deal is to sell you an alarm system.

And while that is hopefully all there is to it, a google search on this turns up several people claiming they were robbed shortly after telling these people they didn't have or want a monitored alarm. There may be no truth to that at all, but its still probably wise to tell anyone you don't know that you do in fact have a 24/7 monitored alarm.