I provide a great number of ways by which to make contact with me: phone, email, the various social media sites.
My contact details are on my many websites, too.
So, when somebody who should not have my mobile phone number contacts me by mobile I will usually ignore them and block their number.
There is no need to contact me by mobile phone and doing so will not only fail to give you any advantage but will put the caller at a positive disadvantage.
I may be old fashioned in this regard but I am determined to retain use of my mobile phone for my family members and the small few individuals to whom I choose to give my number. I am determined to retain one channel of communication that has some degree of exclusivity and privacy.
Because nowadays virtually everything else is in the public domain.
But I want to retain one, last bastion of privacy.
You have been warned. If I have not given you my mobile number, don’t call.