Don't splurge on advertising and other upgrades without making sure that you'll have enough to restock your inventory. If you run out of items in your inventory, and you don't have enough money to replenish it, well, then, you're stuck! Get the music and register first, then start smashing the advertising button! Watch the profits roll in! Enjoy the game everybody! It took quite a while to make: the upgrading, items disappearing from shelves as the inventory goes down, customers coming in faster based on different conditions... I hope to add in some more features in the near future, including a leaderboard!
Big thanks to http://www.bensound.com/ for the music. Everything else by me (including some of the art)