I also believe the note, together with the totality of the crime, was part of a plan to "punish" or torment the Ramseys.

But it seems completely unnesessary to write anything more than a perfunctory note: "If you want to see your daughter again you'll wait by the phone until we call...notify the cops and she's dead".

That being the case, I have a hard time thinking all that other extraneous wordiness was just clap trap or time filler. The logical answer, it seems to me, is that the note is the way it, in order to accomplish the writer's purpose, beyond tormenting or controlling the family and serving as a deterrant on the stair.

Specifically, it set the Ramseys up for the kidnapping call to the police which led to the FBI textbook conclusion that "they were good for it". It really is simple in this, it's primary purpose, and thus affords the writer the secondary pleasure of outwitting the dumb cops/FBI, whom he distains as much as the Ramseys.

What if the call had never been made...the RN warning being taken seriously? A day or two gone by, a trip postponed, a lot of money collected, at least in terms of cash on hand, and it would look like they were trying to buy time to figure out what to do-the note would justyify that-to hide the body or leave the country?

In a short time, the body would have made itself known and the Ramseys would have been just as vilified as they have been.

Either way, the note would have served it's purposes. A drunk, high as a kite, loner, fantasy following pedophile didn't write this note in a few moments; Somebody gave a lot of thought to what this note could do.