I did a survey this summer so I could find out what people want (I will be selling come October when my insurance is due) and most people said 8 oz because they get more for the money. I had a 4 oz from a friend last year when my son was born and it took me quite a while to use it. I have dry skin that is really bad in the winter, so I use more then. I think I will start out with the 8 oz and if it doesn't seem to be going, I will use the 4 or 6 oz. Also, I would use a pump with the bigger bottles and a squeeze cap for purse size or smaller. It really is hard to know what customers will want, guess that is part of the fun of this business! Steph