Like the other commenter, I've never had this happen. If I tipped way below what other customers tip, I would like to be told politely and then make a choice ab

Like the other commenter, I've never had this happen. If I tipped way below what other customers tip, I would like to be told politely and then make a choice about whether I was going to tip more, but I think even that would be frowned upon by business owners or managers. Usually, if I'm not sure (such as a service I rarely use), I will ask somebody what a typical tip looks like. A good example is a buck a bag for bell staff at a hotel - or $5 a bag for Skycaps, if you would like them to ignore the weight of your bag ;)