Messaging apps are proving enormously popular across the globe; WhatsApp CEO Jan Koum recently solidified that point by claiming that his company's service has grown even bigger than Twitter. If that wasn't enough to give mobile operators pause, a new study from Informa may do the job. The research, conducted on behalf of the Financial Times, concludes that chat apps have overtaken traditional SMS in terms of message volume. By the end of 2012, more messages were being sent with WhatsApp, Kik, and manufacturer-driven solutions like iMessage and BBM than through regular text messages. SMS has long been a massive source of revenue in the mobile industry, so the consumer push towards free-to-use replacements is a worrying development for carriers. EU Commission VP Neelie Kroes was quick to highlight the finding.

The crisis isn't immediate, however; SMS is still far ahead in overall user count, and Informa expects providers to rake in $120 billion from texting this year. But momentum clearly favors the up-and-comers, with message output expected to reach 41 billion per day in 2013 – double the number of forecasted texts. Koum said WhatsApp already processes 18 billion messages each day, so the firm's prediction isn't exactly unrealistic. Of course, these messaging apps also need to land on a successful monetization strategy at some point, and it remains to be seen if users will stick around once a price tag is attached.