This worked for us(its a total fib but hey needs must)..we have residential property across from shop front...some light fingered rogue had taken a shine to helping themselves(like you not much of a frontage,as not really many on foot passers by)
We placed a fairly prominent sign at front of shop saying that the retired couple across the road were keeping an eye on the shop front..."You have been warned"....the thieving stopped...and we dont even have a retired couple that im aware of living anywhere near the shop...

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seldom rong!!!!