There are 30 full color stamps that you can get for only ten cents. The ad explains, "U.S. & U.S.S.R. in space on 30 genuine postage stamps by 10 foreign nations. Get bizarre mutants from galactic zoos. View the Apollo splashdown. See the historic Soyuz-Apollo link-up, tracking stations, lunar landing module & more. You'll also receive other exciting stamps to examine free. Buy any or none, return balance, cancel service anytime - but this set of 30 stamps is yours for just 10c! H. E. Harris & Co., Dept. SP-11, Boston, Mass, 02117"
There's another similar ad found in Marvel Comics' What If? issue 9 ("What if the Avengers had fought evil in the 1950's?") cover date June 1978. The ad's titled "MOON & OUTER SPACE" "44 Full Color Stamps - only 10c!". At the bottom it says, "BUNKER HILL STAMP COMPANY" "BOX D. DEBT. JB-24, BOSTON, MA 02117".
While we're talking about What If? #9, I'd like to point out two other Star Wars moments in that comic. The first is a funny Star Wars action figure ad that I've posted elsewhere on Strange Star Wars Collecting. Also, I found the ad below telling us how great Howard the Duck comics are, which parodied the classic Star Wars phrase with, "MAY THE FARCE BE WITH YOU!".
And diving back into Flash #268, I thought I'd go ahead and show this vehicle from a Battlestar Galactica model kit ad that I always thought looked like it was influenced by an X-Wing fighter. They call it the Colonial Viper.