Whatsapp was created because telecom operators have crazy pricing for SMS (5000% profit margin last time I heard). So, people saved on money and limitations (India has a 100 message limit/day) with their data pack.

Hike wants to create an app that goes back to the SMS model where they pay the charges, not the users. They use a mass SMS gateway which is much cheaper. Using mass gateway also means the users must opt out of "Do not disturb" registry, which opens gates for more spam.

Interesting part is, it's backed by a large telco in India[1].

[1] "a 50:50 Bharti Softbank joint venture"