I think Sphere Platform - Social Activity Token (SAT) would be a good investment for 2018. This is a decentralized social network project.
Why?
This has a lot of potential in case it will get traction and get adopted.
It has a nice incentive to earn tokens: "With every click, with every social connection, and every loaded page you can earn serious cash as we build a better decentralized social network together, taking back the power and profits."
Unlike other projects who sell you only dreams, they already have an existing product (you can already download the beta version from Google Play and App Store).
The project is in a presale phase currently. The price is 1$ for 20 Tokens Pre-ICO, but what’s cool about it is that you can sign up for Pre-sale Sphere Wallet & Get 100 Free Tokens. Also when a friend signs up using your unique link, you also get 100 tokens.
So you can be an early adopter and get some free tokens or start with a very low investment.Here is my referral link in case you want to get registered and receive the 100 Tokens for free: https://sphere.social/?ref_code=5309-235efcb4