If you want it NOW, you want it immediately. Immediately means this minute, this moment, right away!
Immediately is an adverb that usually applies to time, but can also mean next to, or nearby, as in, "The kids immediately to your right has red hair." It can also be used to talk about close, even direct, connections, as in, "Are you immediately involved in the push to get rid of the schools superintendent?" Despite the different uses, the meaning is similar. When you see immediately, think close, sudden, and now!