1) Acknowledgement you (as a costomer) exist - at least a verbal greeting but preferably a "can I help you?"
I have had several family members work in retail and it's a basic principle. Some shops train their staff to speak to a customer within 30 seconds of them entering the shop.
I have been in a few bike shops where I have walked in, walked around looking at things, evening picking the odd item up, and the staff have been doing paperwork or chatting to their mates like I wasnt there - depite the fact I was willing to buy something and not just browsing. Needless to say I went and bought off a shop that talked to their customers.
2) Service. Just good old fashion service.
Bookmarks