We are offering free WiFi to our customers and would like to get something back, i.e. their email address so we can contact them about special offers and events relating to our business.
It would be ideal if this could be done at login with the email being entered and captured.
Thank you for the question. Sputnik has a self-sign up you can use in the 'Users' module. However, the e-mail is not a mandatory field, and there is also no way to verify that the email you get is valid.
Sputnik is currently working on social integration as authentication to address such requirements.
We also have an SMS authentication module which would allow a different way to be in touch with customers.