Brief Summary
The Set-Up
Britain needs cash money. So they're going to impose a tax. In order to impose a tax, though, they first have to write a really detailed document.
The Text
Taken on its own, the Stamp Act is pretty unremarkable legislation. It's just a list of how much everything is going to cost under the tax and the necessary framework to make it enforceable. Think of it like how Captain America suddenly has super-geometry powers (yawn) when he bounces his shield off stuff to knock Hydra agents out.
Without knowing the context, it would be pretty easy to dismiss or to gloss over it. The Stamp Act becomes interesting only after knowing the environment it had been released into, and what came out of it.
(Psst: the United States. It was the United States that came out of it.)
TL;DR
Everything printed on paper is going to cost more. Oh yeah, and dice too.