Research on the effectiveness of dating websites indicates that

Research on the effectiveness of dating websites indicates that
 
  a. websites using mathematical algorithms to match couples by compatibility are far more successful than more traditional ways of meeting a partner, such as getting fixed up by friends.
  b. people tend to send messages to fellow website users whose attractiveness and popularity levels are similar to their own.
  c. these sites are very popular among gay and lesbian users, but not among heterosexuals.
  d. the more you find out about someone you met online, the more you tend to like that person.