Actually this game is far too easy. On day 70 I regularly sell 250 to 300 records each day with not a single customer lost. If you let your customers walk long ways (think "record store tower defense") and place some audio booths the line will never exceed 4 customers. In the beginning focus on not losing any customers by patiently increasing records capacity before investing in advertisement. Before switching to a new location be sure to have around 5k funds.
Here's my level 8: t,3,9;t,11,9;c,1,11;t,1,7;t,13,7;b,6,7;c,13,11;m,7,13,180,3,wwcrolwwwwww;m,7,11,270,1,wwwwcuuoddww;m,11,11,90,1,cllollwwwwww;m,13,9,180,1,wwwcrolwwwww;m,3,11,90,1,crrorrwwwwww;m,9,7,180,1,jwwwwwwwwcuod;m,7,5,90,1,wwwwwjwwwwwwcrroll;m,1,9,0,1,wwwclorwwwww;m,3,7,180,1,jwwwwcrruodll;m,10,7,0,2,wwjwwclwwwwlorr;
I would like the Knight to have more colored areas. It is mainly gray and when it's partially covered, it's hard to make out, which one belongs to your army and which to your enemy's.