When TF2's Scout received his update, the ad on the game's blog was done in the style of an old-school mail-away. And you know, some people actually responded. What's more, Valve responded back.
Yes, people stupid/smart enough to print out the coupon and send it in have been getting real letters in the mail. Real letters from everyone's favourite Australian, Saxton Hale, whose company has about the best multi-purpose mail-out we've ever seen.