I know that it first came out in 1981, but when exactly did it really first become popular? It was first broadcast in New Jersey even before New York City despite originating in the city. Did MTV become popular in various cities the moment the cable companies in that city added it?

I reckon they were polular right in 1983 when they started!

They sure ruined it!!!

Did MTV become popular in various cities the moment the cable companies in that city added it?

That and plus when they start broadcasting in stereo thru the Cable Box which added to its appeal for younger music lovers with big stereo systems. Back then if you want to hear variety of good music and songs that local FM stations never played, you watch MTV channel.

MTV Opening Logo:
https://www.youtube.com/watch?v=lV-TJGHGBG8

I prefer MONO so them adding stereo didnt do anything for me....

Im pretty sure watching stuff over analogue cable was MONO anyway as there was only 1 wire coming in... (Stereo would have 2 I think)

I prefer MONO so them adding stereo didn't do anything for me....

Back then most TVs (and even today) had one or two tiny speakers so Mono or Stereo audio didn't make much of a difference. But if you route the audio thru a decent audio system, the difference become obvious :)

I'm pretty sure watching stuff over analogue cable was MONO anyway as there was only 1 wire coming in... (Stereo would have 2 I think)

One wire is all that is needed as Cable is also carrying analog TV signal. The Cable Box or TV's Tuner select the channel, decode the video and audio and send it to your TV.

Yup indeed my friend :)

I remember going over to my friend Gail's house and seeing MTV for the very first time and that was in 1982.