I've read the other posts and chime in, specifically with
1. Great fabric choices, different than the things readily available from Joann or similar and not just cutesy groups of pre-matched fabrics. Color and beauty.
2. Genuinely friendly helpful sales staff who don't lecture.
3. Evening hours at least one night a week.
4. Cool classes - not some dreary ugly pattern and fabric you wouldn't want in your home and couldn't give away.
5. Nice work space for classes/workshops. Elbow room.
6. On-line presence to showcase NEW fabrics coming in, sales, etc. and fabric inventory.
7. A place to stage fabric choices, without knocking over some cutesy decorations or worse a lineup of bolts.
All that said, I think that to succeed in today's flat economy, you really have to know your market - who will visit, who will buy, how much will they buy, what is max size of market and what share will you get (Walmart or Joann's nearby?) what is per capita income in area, how many women don't work outside the home, distance to travel, how appeal to demographic (quilt hops, shows, guilds, girls-night-outs, sew-together evenings, tea and cookies, guest quilters, fabric designer visit, organize trip to mfgr., etc), hobby or passion quilters or pros, long or short armers (rent out the LA?) special orders of quilt hi-tech specialty stuff ... huge marketing effort, charm and cachet. Sound like a lot of fun!!!