Something not bad to know is that there are from 17% to 23% of bitcoins that are gone for good according to chainanalys. It's about 2.7 to 4 millions bitcoins.
http://fortune.com/2017/11/25/lost-bitcoins/ 
It's a so huge number if you think about it would mean that once all the bitcoins are mined we will have about 6 million bitcoins lost forever. So if finally, we have fewer bitcoins circulating the value will go above the roof?