I am not completely sure yet...
In my case, it is a group of women who order from United, once a month in bulk.  You can share with others if you do not want a whole case of something.  Sometimes there will be someone else who will want say half a case, then you split the cost with them.  If there isn't, you needA truck delivers it to a predetermined location and you pick up your items that you ordered and pay the coordinator for them.  She then pays the company.  A lot of these women either have food allergies or have children with food allergies and order specialty items from United.  I ordered a case of Muir Glen tomato sauce and tomato paste.  I also picked up a case of Taste of Thai Lite Coconut Milk.  I have trouble finding certain brands that I have come to like, so this is perfect for me.  I am going to stock up on the grains and beans that I use a lot. They also have frozen and perishable items, but I haven't made it through that list yet.  Last month I had to look online for everything, but this month, I received a catalog in the mail that I can sit down and really look at.
For example, so far for next month, I am ordering 5# of organic cannellini beans/11.20, 5# of organic pearled barley/6.38, organic black beans/8.29.  I could save quite a bit more by ordering 25#, but I am not sure I want quite that much right now.  I will see how the smaller amounts work out for me first.