Ha, Sea Monkeys were the only thing I ever bought from one of those comic book ads. Not for lack of wanting them-- I definitely had my eye on those x-ray specs. But not only was my meager allowance not going to afford much, I didn’t have the patience to wait 6 to 8 weeks.
Anyway, talk about a letdown! I was only 6 or 7, though was still sensible enough not to expect them to be anthropormorphic and create a tiny undersea Altantis-style kingdom in my fishbowl, like the ad pictured. But the few ant-sized brine shrimp that hatched were extremely anticlimactic. All but one quickly died. The lone tiny brine shrimp held on to life and swam around until one day I accidentally knocked the fish bowl off my dresser when I pulled too hard on a stuck drawer. I remember the lone Sea Monkey swimming in a puddle on my bedroom floor until my mom unceremoniously wiped it up. I started to say- “mom, wait…uhhh, eh, never mind”.
ETA: I started a separate thread:
Did you ever buy anything from those old 70s era comic book ads?