Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
When you see something you like, rather than ordering immediately you can tell it to add the item and a quantity to YOUR wish list instead. Later, in minutes or months later, you can go to the wish list and select items you want to order and put in your order basket.
You can also use it to build a list of items you want, for Christmas just for example, and then let other people browse the list on those things. I believe they can then select from one or more of the the items and order them themselves. Or they can peruse the list and get the items someplace else for that matter -- the important thing being they will know those are items you definitely want!
Very useful tool.
Ken