From what I understand and read in Revelation 13, all those not written in the Book of Life will receive that mark.
Revelation 13:7-8 (speaking of the first beast) "It was granted to him to make war with the saints and to overcome them. And authority was given him over every tribe, tongue, and nation. All who dwell on the earth will worship him, whose names have not been written in the Book of Life of the Lamb slain from the foundation of the world."
Later it chapter 13, it says (speaking of the second) "He was granted power to give breath to the image of the beast, that the image of the beast should both speak and cause as many as would not worship the image of the beast to be killed. He causes all, both small and great, rich and poor, free and slave, to receive a mark on their right hand or on their foreheads, and that no one may buy or sell except one who has the mark or the name of the beast, or the number of his name."
Then consider the scripture that Enid showed:
Revelation 14:11, "And the smoke of their torment ascends forever and ever, and they have no rest day or night, who worship the beast and his image, and the whoever receives the mark of his name."
"He who endures to the end shall be saved"