That's the finding of a Pew Internet and American Life Project that found that three quarters of teenagers use instant messaging, and the average amount of time spent sending the quick electronic notes has increased over the last four years.
For the majority of teens, email has become the method for communicating with adults, such as teachers, and institutions like schools, and as a way of sending lengthy and detailed information to large groups.
"They see email as much more formal, similar to how adults would see written letters: a quaint way of communicating with older relatives or for formal communications," Pew researcher Mary Madden said.
Teens are using instant messaging daily for conversations with multiple friends, the study found. Those conversations range from casual to more serious and private exchanges.
As a result of the constant use of IM, away messages have become popular among teens, who use them to keep tabs on each other's doings.
"There's a sense of needing to always stay connected and having this persistence online," Madden said. "Even if friends don't IM each other everyday, they still know each is OK and around because they're logged in."
How the expectation of instant communications will affect teens as they become adults and enter the workplace is difficult to say, Madden said. "Technology is changing so quickly, that it's hard to anticipate what people will be using in 10 years to communicate with each other."
Nevertheless, the intensity of IM use would probably wane, as teens get older, Madden said. But the love of IM probably would continue in college, since "we've seen with young adults the same trends and love of instant messaging."
The study also found that nearly nine out of 10 teens use the Internet, with half of the 21 million online teenagers using it everyday. This compares to 66 percent of adults who use the web.
About eight in 10 teenagers play games online or get news online, four in 10 have made purchases through the Internet and three in 10 use the Internet to get health information. All these numbers show are significantly higher than what Pew found in a similar study four years ago.
Cellular phones are being used by 45 percent of teenagers, and many use several devices to connect to the Internet. Many teenagers log in at home, school, a friend's or relative's home and the library.
Nevertheless, the landline telephone remains the most dominant communication medium in teens' everyday life, the study found. While surprising at first, the finding make sense, considering that many teens use the family computer and cellular-phone operators charge by the minute, Madden said.