A growing body of evidence suggests that the ubiquitous text message may now be regressing from its peak popularity in some markets, most recently underscored by a series of statistics released by Finnish carriers Sonera, Elisa, and DNA around SMS volume on Christmas Eve — traditionally one of the busiest texting days of the year. Sonera, the nation's largest wireless operator, says that 8.5 million messages were sent on the 24th versus 10.9 million a year prior — a decline of some 22 percent — while Elisa and DNA report that they saw drops of one and five percent, respectively. Though it's just one country, Finland has long been a bellwether for mobile trends: it counts Nokia among its residents, of course, and it pioneered GSM in the early 90s (and the 1G NMT standard prior). Needless to say, Finns are among the most mobile-savvy people in the world.

The decline, for some, might come as a surprise — virtually every other aspect of wireless is growing unbounded: smartphone saturation, data use, and so on. Indeed, those very trends might be the humble SMS's downfall. A growing theory is that messaging is losing ground to social networking services like Twitter and Facebook, both of which offer rich experiences on smartphones attached to high-speed data networks that are becoming more ubiquitous by the day. Traditional text messaging — which lacks native support for rich media and contact groups — simply doesn't have the flair and visual appeal that newer services do. Facebook's latest published statistics indicate that over 350 million people use their phones to access the service.

Is this the SMS death knell? Not exactly: messaging is still growing in the US, though a CTIA study in the middle of last year reported that its losing steam (seeing how the messaging trend took off in the US long after it did in Europe, it'd make sense that Finland would be an early warning indicator in that regard). Also unaccounted for are emerging markets where neither high-speed data nor smartphones have yet made a big impact; services like Nokia Life Tools specifically account for this, relying on SMS to ferry bite-sized pieces of data back and forth. In other words, SMS is definitely here to stay — but between social networks and data-centric technologies like iMessage, the days of the must-have unlimited messaging plan may be drawing to a close.