Do u have bitcoins just waiting in you wallet not doing nothing not earning you intrest or making u any more bitcoins 

Wel that what thus doubling sites are I'm not sure how why do they work bug there are loads popping up but are they your answer told question above 

I 50/50 at the moment but soon will make up my mind 


What about u have u used them did they work 

Why not write a post do we can now if it a good idea

Hope so one does I been reading it for sure