This expands on https://worldbuilding.stackexchange.com/a/3433/2700"Redundancy",but I felt it too large to be a suggested edit.
Not thousands of copies: millions, or even billions.
You know why we can still find dinosaur bones?Yes, bones are kinda durable, some chemical properties etc.But the fact of the matter is, there were many dinosaurs,and the ones we find, are the tinyiest fraction of a faction that happened by chance to endup somewhere that preserves them well.
For super long-term storage you are targetting are the archeologists.They are the people with the interest and expertise to recover and translate the messages.
- Print it in a book
- send it to every library, archive and museum etc in the world
- This is where future archeologists are going to start looking for information.
- Some will (sooner or later) destroy it; but some small fraction will maintain it as they preserve other things in their collection.
- Print it on microfilm, and burn it to CD, and any other compact media
- run a publicity campaign asking people to try and store it, e.g. in household time capsules.
- Send it to everyone who asks
- get it digital, and try to get a copy onto every device
- A virus would be effective in the short term, but would likely turn public sentiment against you.
- Something like having a free copy of it included in every ebook reader (ebook app) would be good.
- Having it be used as the secure erase overwriting data common OS system/security suite would result in it being on millions of thrown out government and corporate computers
- Do everything else in this thread, not once, not a dozen times or a a hundred times but as many times as possible.
Sure all these things have a a very finite life span, but they are really easy to do. All you are trying to do is get lucky.You are buying 1 million lotto tickets.