You don't have to know people at a MAC store to pre-order but it certainly doesn't hurt. Building a relationship with a SA/MUA is helpful because it allows them to get to know you, your likes, dislikes and preferences. I have met some of the most wonderful people at my local MAC store who look out for me and who I consider to be friends. From day one, upon walking into this particular store, every single SA acknowledged me and
every person who entered. This was not the behavior about which I had read regarding some other MAC stores...rude SAs, etc. This is truly an amazing group of people. I also ordered from a MAC store out of state because my local store was out of an item that I failed to pre-order, and later wanted. My store referred me to a store in New Jersey and the SA who happened to answer the phone was really nice, took my order, shipped the merchandise & enclosed a sweet note.
Give it a shot!