I can only tell you my experiences as a non-American who never had a breakthrough in your country, but here it goes:
I was very close to going the way of the examples
@Sgt Zogbot Delta Operator gave above when Genesis stopped making new music (I've told this story many times before) and ended our version of the band. I had to fight through depression and major monetary loss for a couple years, but thanks to some good friends (love you always, Pauline) and discovering my music had a good following in certain parts of Europe, I was faced with a choice: continue making music for the love of it and just live wisely, or own up that I was only in it for fortune and fame and find another road to travel.
I couldn't give up what I've been doing since I was a wee lad, so, I've saved up and invested over the years, and I live a cozy but not opulent lifestyle. I make sure my bandmates are compensated fairly - I'd never hear the end of it from my brother if I didn't - and we book venues and areas that we're in demand and can fill.
No crazy record contracts, no insane mansions or Bentley's, no bacon egg and cheese on a roll every morning, but I do well. Not "Cribs" worthy, but a healthy living. I'll never make, let alone spend, what someone like Sinatra or Prince did, but I get to do what I love for a career and I can never complain about that.
Hanson does extremely well as a nostalgia act. They have a following like The Dead and Phish do, just a little classier.
I keep my nose clean, brother-san.
And
@Nigger John, was it Spacehog?