If you are unlucky enough to receive a sextortion spam email, don't panic and don't pay. Don't click any links on the email because it may contain malware.
The sad truth is that most victims have little to lose. It's a "spray and pray attack," a volume play executed by botnets, targeting a vast list of email addresses whereby a small percentage return will be lucrative. It's the ultimate in self-selection—the people targeted with the most to lose are most likely to respond.