The United States and Canada is catching up. Asia and Europe currently send 1.4 billion SMS a month*, but North America is not far behind. In July of 2002, North America reached 1 billion SMS a month**. The number will continue to rise as wireless carriers allow SMS messages cross-carrier capability. Usage increased 400% in the North American market when carriers allowed their customers to send SMS to different carriers.
WAP vs. SMS

Certainly with the advent of WAP, SMS will never reach popularity in North America. Such an assumption is wrong. Examine the differences:
SMS is cheap, WAP is expensive. SMS is instant, WAP is slow (transmission is 9.6 kbps). Customers held no expectations for SMS. Expectations were high for WAP, and low customer satisfaction shows that the expectations were too high. SMS is user-friendly, WAP is not. You can download games, music, videos, pictures on WAP. You can now do the same with SMS.
SMS enjoys all these advantages, plus usage increases during holidays and special events such as birthdays or anniversaries.
SMS and youth

Unexpected results have come from SMS usage and youth. One recent study found that the percentage of youth that smoked dropped significantly since the inception of cell phones. It seems they have something else to do with their hands.