The Customer Paid
Nothing is free. No matter the product or service, it must be paid for.
It could be cupcakes left on the counter at your office, extra pitchers of beer at the local pub, lifetime email access or storage of all your digital family photos.
You may not have been asked to pay cash out of your pocket, but make no mistake, it was paid for.
The rule is quite easy to remember... Either you are a customer, or you are the product.
In my list above, the cupcakes are easy to figure out. Obviously someone in your office either bought them, or bought the ingredients and made them.
Beer at the pub? The pub bought that keg from the brewery, but eats the cost, instead of passing it along to you. Perhaps the nachos cost a little more this week instead?
The free web services are no different. It costs real money to set up and run all those computers required to store all the email jokes, love letters and photos for millions of customers. Who pays for that?
In the case of a company like Google, they charge other companies to show their ads while you use their web pages.
For an advertising company, the more they know about who is viewing, and potentially interacting with their ad, the more valuable it is to them.
So Google reads your email, sees you're planning a group camping trip, and suddenly you're seeing ads for canoes show up everywhere you go on the web.
So, yes ... you did not pay for the email. Your personal data paid the bill for you.