There has been a lot of talk recently about how mobile instant messaging will threaten SMS. Our experience so far is that these two services are complimentary, rather than competitive, and furthermore that user are prepared to pay for both.
Mobile instant messaging is still relatively early in adoption, not least because it requires users to be on a data tariff from their operator – still a fairly expensive commodity for most price plans. Additionally, the handset specification required to support Instant messaging is very high, and is therefore outside the capability of most handset on that market today.
The advantages of SMS lie in its ubiquity and coverage, both geographically and across the base of mobile subscribers. Mobile IM will undoubtedly grow, but it has for the foreseeable future it will very much be a niche application.