The average person is not using a calendar and is not getting more than 1 relevant personal email per week.

Most people use their personal email extremely sparingly and it is inundated with promotional / account-related materials which are already handled rather deftly by most mainstream email providers

Ha, tell me you don't have children without...

lol no one is getting personal emails, maybe some people get one every few months, but most probably never (not taking into account other than order/shipping confirmations, login codes, etc)