A lot of us just looked at them and wished we had the scratch to get them. At some point my brother and I were lucky enough to get our parents to order us a couple sets of these guys. I've heard some people complaining about disappointed when they got their soldiers, but we loved our sets and spent many happy hours setting these 1" tall figures and fighting imaginary battles. According to The World of Comic Book Toy Soldiers these figures came from Lucky Products or a "Nameless Mail Drop Company" and not one of the better known companies like Helen of Toy. Actually, the above page seems to cover this subject pretty well.
Even luckier, these little guys survived. Below are a few photos of them:
Below is another ad for these soldiers with an actual photograph of them. Some of them look a little different than mine. Some of them, particularly the artillery and cavalry look like the much maligned "flats" that I hear resentful baby-boomer complain about when they talk about sending away for these toys.
Here's a fun page from 2004 that contains a review of a new incarnation of Helen of Toy's Classic Army Men Footlocker. Unfortunately, the 2004 version of Helen of Toy didn't seem to last. Below are some more toy soldier ads from the backs of comic books, click on them for larger images.