What is an .onion domain?
.onion is a special-use top level domain suffix designating an anonymous hidden service reachable via the Tor network
Contrary to the regular domain names, the .onion domain names cannot be randomly assigned,
as they are generated in a cryptographically secure way.
This is why they usually look as a random 16-symbols long line of letters and digits; e.g.
3g2upl4pq6kufc4m.onion is an .onion domain
for DuckDuckGo search engine.
Why bother launching your site in Tor network?
Tor is the secure network where the actions of the user are anonymous and cannot be traced, preventing privacy risks for them and avoiding unnecessary surveillance or wiretapping by malicious parties (or, on some markets, even by oppressive governments).
Using cryptographically strong facilities like Tor may be your only way to enter the markets where your service was previously inaccessible. This is the reason why we accept payments in Bitcoin.
Launching the “hidden service” in Tor network gives your customers the level of personal security previously available only to the undercover police agents!