Imagine this: You receive an email, apparently from a reputable source, such as Best Buy, where you had recently purchased a flat screen TV. The email states that if you click on the link, you will instantly receive a $25 gift card good towards your next purchase. You had your eye on a brand new blu-ray DVD player to go with that nice TV you just bought. Why not? So you decide to click on the link.
Oops. You probably shouldn’t have done that.
Your machine is now infected with malware and to secure your data or block further nefarious access to your computer, it is demanding that you pay ransom.