The opportunity is much higher for you to get to know the person you are interested in, because their profile gives you an idea of the person's personality, interests, likes, dislikes, ethnicity, religious background and so on before you get to meet them in person. Email and instant messaging are also popular methods for people to communicate with each other. The cell phone is also practical, (do not recommend giving your home number while in the first stages of getting acquainted).
Another reason why online dating is so popular is because teen chat it eliminates the fear of the rejection factor as well as the social awkwardness that one might feel when meeting someone new, because initial interaction is anonymous throughout most online dating websites.
CONS: There are still people who will join dating sites just to look at profiles, even if they are not interested in dating. So you may be interested in his/her profile but he/she won't be interested in yours. The numbers of women who have joined the online websites far outnumber the number of men. Good for the men who have joined.