Here’s one way to understand the difference between project work and providing support:
A one-time project is like a one-night stand. You are strangers and don’t know each other at all. You do it once and never see that person again.
Occasional project work with a repeat customer is like a booty call or friends-with-benefits. You might get in bed together once awhile, but you’re there for one thing with no other strings attached. There’s only a very superficial level of familiarity.
Providing administrative support is about being in a relationship with a client. You’re both there for the big picture and know that initimate knowledge and understanding of each other can only be shared, grown and deepened in an ongoing, committed relationship.