Since this thread was moved/merged, I think it lost a few replies. One of them was Santa's reply mentioning that you have to play on higher difficulties to get more fans. In Rock Band 1, there's a cap for fans for each difficulty.
See these old threads for more details:
From one post in the second thread:
Also to note:I think [the cutoff is...]
100,000 [then] you cant get fans on Easy
300,000 [then] you cant get fans on Medium
600,000 [then] you cant get fans on Hard (This much I know)
Over 1,000,000 you get a ton of fans... but as I said over 600,000 you have to play Expert or you wont get no fans anymore.
Also when you play setlist you play before... if you got 5 stars in it... you must get ALMOST or EXACTLY 5 Stars on each song to get fans. (Or Gold Stars)
Around 4 or less I dont think you get fans.
Hope that helps!The lowest member determines the difficulty. There is a cap for fans on medium and hard. You will both need to play hard to gain more fans.
5+ years, 4,000+ songs, 1 awesome developer. Thank you!