I have suscribed to Zoho one expecting to see an increase of the size of my inbox in Zoho email but that did not happened. Why?

I have suscribed to Zoho one expecting to see an increase of the size of my inbox in Zoho email but that did not happened. Why?

I need help. 
I have signed up for Zoho one expecting to see an increased to the size of my inbox and that hasnt happened.
I dont care about the other applications to be honest, i just need more space for my inbox.

Thanks.

Stefano