Telecom companies in India fear from OTT telephony:
OTT telephony is the technical name of the VOIP or Voice Over Internet Protocol. Apps like Skype, Viber, What’s App, BBM etc. which offer voice calling fall in this bracket. While broadband providers have no problem, telecom companies feel threatened by these messengers which provide talking facility.
How so many third-party messengers came into existence?
Water flows downward. So does consumer. It will always find attraction in lower tariff possibilities. So how so many messengers came in to being? Because telephone companies became greedy. While they sell bunch of hundreds or thousand commercial SMS for 1 paisa or less, they charge at least 1 rupee for normal personal SMS. Thus they subsidised spam at the cost of average consumer. Of course developers saw the anomaly and found a solution in instant messengers.
Sandeep Bhalla's Blog 