Not really - I signed up and mined BCC without spending a cent. On the finance and earning interest side there's also companies like this:
https://www.bitbond.com/
You can certainly earn interest on BTC. What I would suggest to watch out for are
'exclusive referrals clubs' - sites you can't join without a referral. Those tend to be dodgy - creating the impression you've stumbled on the next best thing while the rest of the world can't get it - anything that creates FOMO. Great infographic otherwise.
And nothing wrong with referrals - just check my sig