After reading my next 25 pages, the literary agent who may potentially represent me, asked for the FULL MANUSCRIPT and an "EXCLUSIVE."
An exclusive means that I only show the whole book to her for a specific amount of time (approx. 3-4 weeks) and then she'll let me know if she wants to represent the project. I went ahead and emailed the other agents I had queried to let them know that I had a request for the entire manuscript as well as an exclusive. The reason you're supposed to let them know is to create interest and hopefully bring your query to the top of the pile. It's the equivalent of saying, "I'm great! Look at me! You want me!" or something like that.
This week, I'm going to go ahead with the exclusive. Then, while we're waiting, responses will be trickling in. They will most likely be rejections (I'm not being modest; I'm being realistic) and that will be fine. If any come back positive, I can let them know that another agent has an exclusive, but that I can give THEM an exclusive after that point. Then, we can try to see who feels like the best fit and/or can negotiate the best deal.
For the record, I'm still in shock.