Instant emails with no signup or password, temporary and 100% anonymouse.
Great to get that spammy offers and promotions instad of your regular email box.
Also, it provides safebox to open received emails that protect from harmful scripts in messages.
Even access log is off.
It makes it easier to start a business, open a bank account, and things like that in Estonia. That's important because it's an EU country with a reasonable tax system, stable government and an overall ease of doing business. Being part of the EU makes a lot of things easier in dealings with other countries depending on your line of work.
That's the theory anyway. We'll see if it pans out.
Personally, it's an important step for me in getting a real residency beyond one tied to a company that isn't my own in the EU.
Estonia has little natural resources, a small population, an unstable neighbour and it is a bit at the periphery of Europe. They have invested a lot of effort into becoming strong in Internet. This is one example of those efforts.