I don't want to sound callous or unsympathetic, because the discussion here is certainly focused on a very serious topic. After all, receiving or not receiving the mark is a life and death matter...of eternal consequences. But I must ask the question, is the Bible the foundation of our thinking or not? Because most folk are so busy looking at technology and the things of the world to answer your spiritual questions you are ignoring the fact that regarding any spiritual topic, and that includes eschatology, the Bible interprets itself.
Yes, clearly there will be financial restraints placed on those who refuse to receive the mark, even ultimately the death sentence...but neither the financial restraints,(through an RFID chip or whatever) nor the death penalty, is the mark itself.
Remember, it is the mark OF the beast. Who is this beast? The beast to which the mark belongs is a global religious empire. The mark therefore is that which this empire imposes on the world as a sign or seal of submission to her authority, it is of a spiritual/religious nature. How do we know this? Because the recipients of the mark are set by the prophecy in Revelation 14 itself as being in direct contradistinction to God's people who "keep the commandments of God and have the faith of Jesus". Revel. 14:12. Remember, we are speaking of an antichrist spirit here...thus the transgression being committed by the bearers of the mark is contrary to, or in place of, the commandments of God. It also reflects that ones faith is no longer in the Creator God, (Revel 14:6,7) but in a counterfeit who claims this spiritual mark as a token of its own authority above that of the true God, but unlike the true God, has to use deception, coercion, force, and threats through the power of state or civil legislation to implement it. Typical ages old Satanic principles at play here. But please guys, we nee to be using the Bible as our source to understanding prophecy. We need to stop prognosticating or using clairvoyance on matters that the Bible doesn't reveal, such as a literal barcode or chip. Do you really believe a chip brings down the wrath of God unprecedented in human history. Come on, think about it. God doesnt care if you use technology to manage your finances. But He does care when you keep mans commandments when they directly contradict His own.