Their offer sounds unrealistic and yet you're still interested? To be a member you need to pay, as well as buy a share, but that doesn't guarantee that you will be a millionaire. You won't be even sure how long would it take to get your ROI.

Aren't you curious if the one who's referring you is already a millionaire by just being a member? Why not ask him  

Bitcointalk post about BitClub Network: BitClub Network: MLM promises, false testimonials and PoS coin - AVOID