Maybe popular is a better word than "famous".
"VCR" became a commonly used word during the 1975-1980 time frame starting with the introduction of the Sony Betamax in 1975. .
The biggest reason for their popularity was the ability to rent/buy movies on tape. Before the VCR you could only watch a movie by going to movie theaters or watching what ever movies made it to broadcast TV (cable TV wasn't nearly as common in those days and things like Dish and DirectTV were pure science fiction).
There were other factors:
Ability to record TV programs for later viewing. That's why I bought mine. Instead of waiting at home for your favorite show, you could do something else and watch it whenever you wanted.
Commercial porn. Video cameras were quite expensive before the mid-1980's, so amateur porn was not a big factor in the early days. But commercial porn was a big factor. Before then people could only watch porn by going to seedy movie theaters. Watching porn also became more of a couples thing as few women wanted to be seen going into seedy movie theaters full of drunks.
There were some VCRs a few years before 1975, but they were not that popular. (There were no VCRs in the 1950s. In the mid-1950s VTRs were developed for TV networks, but they were very large and used big spools of tape. I'm thinking they were about $50,000. In 1956 that was a lot of money, perhaps $200,000 in 2008 dollars)
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I almost forgot. The movie industry did not want people to own VCRs. They fought in the courts to keep people from having them claiming they would destroy the movie industry. In 1984 the US supreme court ruled against them.
Kind of like the arguments made record companies in the 1920's about how radio would kill the record industry.
