Like previously stated, and it is absolutely right, Don't block your windows! Post your signs on the interior walls. If you have video cameras make sure they view the doors and registers, and for pete's sake change the tape at least once a month,I have personally viewed many tapes of robberies that were for the most part useless because of poor quality grainy video,Don't go cheap on the tape.The best I have seen are the digital recorders, but of course,they are expensive.You may or may not want to be behind bullet proof glass with a revolving window which business is conducted from,but it tends to decrease customers, I get that from fast food/convienience stoor owners in Chicago where I am a Police officer.It's kind of a trade off between safety and profitability, I suggest opting for safety.