Do you Hate Giving your Age Online?
When Landing Pages Don’t Ask for Age, the Conversion Rate is Higher
I found that landing pages that asked users for their age tended to have much lower conversion rates than pages that did not.
I then analyzed pages that asked for telephone numbers (or suggested that the user would be called).
I found that pages referring to telephone numbers or calling had lower conversion rates than pages that did not.
Lastly I examined pages that asked users for geographic information.