I was living in Australia in 2000 and texting was more common than calling because it was cheaper to text than call. But in the US it was the opposite. You had unlimited calling, but plans around that time had a different pricing scheme for texting (can't remember the exact details) so could be one reason why it took the US a bit longer to finally pick up texting. I remember it was about a year or 2 later that I felt texting started to become more common in the US.