Appliance outlets were pretty common on clock radios in the 50's and 60's. Just as with the ad in that collection on YouTube, the advertising for that feature often promoted the idea you could use it to automatically start the coffee maker in the morning. However, since the usual suggested location for a clock-radio was the bedroom (so it could wake you up), I wonder how many people actually decided to keep the coffee maker in the same room as their clock-radio just so they could actually have such automation in their home.
As for the rest of the ads in that collection, some of the more interesting to me were the RCA-Whirlpool appliance ads, since I don't generally see as much promo material for appliances. In particular, it seemed odd to see ads for RCA gas refrigerators-- not only because I figured Servel was about the only company still manufacutring gas refrigerators in the 1950's, but the fact that those RCA ads actually *touted* the fact that they were gas-operated instead of electric as if that was some sort of great new thing..! ...Though I guess with that automatic ice maker, those refrigerators would have still needed an electric outlet, which would negate one of the few possible real advantages of a gas refrigerator.
[Gas refrigerators were pretty reliable since they don't have any moving parts (or at least don't *have* to have any), but as far as I know, they were usually much more expensive to run that a mechanical (electric) refrigerator (unless gas was *really* cheap where you lived), and weren't generally as effective in terms of cooling capacity.]