nomistakes said:mcdonalds can do the same too...lets face it is not profitable to have someone waste time, who does not order much...could depend on personel and their judgement.
That's overly simplistic thinking.
If you want people to think your establishment is not fun, not happening, not friendly, and does not sell good products, then by all means, chase every customer out the door!
Because an empty cafe is unattractive.
If however you want people to think your business has something of value to offer, such that they come in and buy something then obviously, you should let lingerers stay.
What Starbucks does is:
1. Use their brand as a draw to bring people in....this is a bad idea.
2. Instruct their baristas to be "fun" and get to know the customers' names.... but baristas usually end up being a pain in the a$$ instead.