What does it mean by 3rd mobile call to action?

The 1-800 number was the original call to action, followed by the next call to action the form fill. Whisp has the 3rd call to action that allows you to build a customer base effortlessly and engage fans, prospects or clients directly through personalized 2-way SMS, without the hassle of lead forms.  By scanning or clicking and then sending the text message they have raised their hand to engage with your business.