What does the Mark mean? 

It is simple, it means ownership and control; in this case it also refers to a forgery of the seal and love of God given to Christians (Ezek. 9:4-6; Rev. 7:2-8; 14:1). 

This “mark of the beast” is about who controls us, Satan or God. This beast forces people to bear the mark as a way to control and also as a counterfeit to the Holy Spirit that “marks” a true believer. This is also a pattern of the stranglehold that has been repeated throughout human history, such as the trade guilds that controlled who could buy or sell in the midst of the church at Thyatira (found in Revelation 2:18-29.) 

Also, it is the corruption as exhibited in John’s time by both Jewish and pagan priests, and especially the emperor cults. It is also represented in countries that are run with totalitarian tactics by corrupt officials and/or dictators. There are countless speculations on this, but it really denotes from the word meaning and the context, that it is a metaphor for ownership and control, but the means by which this will occur is unknown. 

All we can do is see how this has played out before and be ready for the future. Fear mongering over technologies and personalities are beside the point; neither Satan nor God need technology to make this happen, because it has happened before in grand scale without it. However, since we do have it… (Eph.1:13; Rev. 14:9-11; 15:2; 16:2; 19:20 and 20:4).