When people buy at a B&M shop they can return the item and get a full refund, without any penalties for the return, as long as they have proof of purchase.

When customers come into my shop should I charge an entrance fee so they can scuff their boots on my floor, take up my time, get my advise, then go away without buying anything.

Some buy and some don't, some stuff around and others are too impatient to wait while I finish with another customer and go without me knowing what they might have wanted.

It's retail, and it's "par for course", I'm sure you've done it too.