The document discusses the impact of over-the-top (OTT) applications on mobile network operators. It notes that while OTT applications have increased data usage and initially benefited operators, they have also shifted revenues away from operators to OTT providers. Operators still bear the infrastructure investment costs but are losing voice and messaging revenues as users switch to OTT applications like WhatsApp and Skype. This trend will continue as more users adopt smartphones and OTT applications, putting pressure on operator revenues and business models. Regulators face challenges in addressing this issue.