Celebrity used to use Michael's Club as a cigar lounge. It was very "masculine" and not a place you would want to "hang out" - so they changed it to a bar with entertainment and did much better. You could smoke at the bar, but not the tables. It worked fine. You could also smoke anywhere at the Champagne Bar, tables or bar - and many areas of the evening lounges. Only the Martini Bar was strictly non-smoking. Arguably, the Martini Bar was more crowded, but there were plenty of us Champagne regulars, and never an available bar chair or table there close to dinner. We all smoked. I'd say the crowds were 65% Martini, 35% Champange - of course, it could be more people like martinis! 
P) In addition, one could smoke in their cabin and veranda. Everything else was non-smoking. And that's a lot of ship. Now it's virtually a non-smoking ship, albeit a few tiny areas, only one of which is indoors and EXTREMELY small in the disco.
I can't speak to other cruise lines, since the before I switched to Celebrity, one could smoke wherever they pleased, except the dining room and show rooms.
So to answer your question, I would say yes, the non-smoking Martini bar did better than the all smoking Champagne Bar, but 35% of revenues is a lot to throw away. And then, you must also consider how many people wouldn't mind the non-smoking bars, but will draw the line at a virtual non-smoking ship? Lots to consider.
BTW - I booked a balcony Marriott for next week, and they have a $600 fee policy for smoke coming in the room, but again, told me they look the other way as long as you "blow it out" the balcony. Should be interesting, since the resort is over 200 acres and that's a LONG walk for a smoke.
