Most good shops of course have painting tables and gaming tables. My reason for changing from my usual spot would be. MORE ROOM. More community competitons. I mean we have one for 40k like once a month for two days. That's not enough.
Willingness to order pieces that may be out of stock. Just make them pay a non-refundable down payment.(Trust me on this, unless you know someone well, or are just trusting, don't order something you don't carry on the without getting that. Or you may be stuck with it forever.
Get a group of employees who LOVE to play beginner games, I would have never made it into the hobby, without the store employees who were willing to play test games. (sometimes with unpainted store models, or whatever) To physically teach the game. I have seen hundreds of purchases at my local Tower Games. Because they were just SHOWN how to play a game of 40k. (They actually double their sales by having a Warmachine/Hordes 'expert') by playing these practice games. Then they waltz them over to the models and BAM big sale.
Make your shop a relaxing atmosphere, sell beverages and snacks. People will want to chill a bit during big matches.
Just some things off the top of my head.