I invested in Deep Onion first because I like the Tor project and they were very vocal about using the tech. They also have donated to the Tor project multiple times which is another plus. Yes, the airdrops are a large thing for Deep Onion and some dump every Friday. However, check out its development and the way the core team has mastered marketing it. This is much better than other coins that go only for development and expect users to flock to the project because of it.