How it usually works:

One person stumbles upon the website and enters the email address of several people on whom he or she has a crush. The above email is then sent to every person on that list. If you click on the link, you will have to provide email addresses of people on whom YOU have a crush. They will notify you if the person who is crushing on you is one of the people you listed, and they will send emails to everyone else you listed. This generates traffic on their website and they get advertising $$.