Although the Bible makes clear no one can predict when the end begins, many have tried. We might do better to wonder how long the devil can fly under the radar once the end is upon us. But since so many prediction have turned out to be false, people may be quick to dismiss early calls to alarm.
This is why it is worthwhile to look at failed candidates for a Mark of the Beast, so we can say why, no matter how many believed at the time, previous candidates could not have been a true Mark. It is important to note that this is a sin that cannot be recovered from. Something about it will prevent men from asking God for forgiveness. The Lamb purchased men of every race, nation, and language with His blood, but once a person worships the Beast and accepts the Mark, they are lost.
No matter how literally you take the Book of Revelations, this standard makes many theories as to exactly what the Mark is look ridiculous. The Sunday sabbath? Are people really lost forever for going to church on Sunday? Currency of the Roman Empire? Can’t buy or sell without money, and Christ noted the inverse correlation between wealth and virtue. But does having some coin permanently separate you from God?
Technology will soon make a device meeting the criteria in Revelations possible. Synthetic telepathy is real, and and non-defense researchers have suggested improved group problem solving as an application. This sort of hive mind doesn’t sit well with me in any case, but if the problem being solved was “everyone should worship the Beast”, then you can see how this would meet above criteria.