Comment by msla

There's two maxims:

You get what you pay for.

If you're the customer, you're the product.

"You get what you pay for" means if you buy proprietary software, you get software from proprietary vendors who act like modern proprietary vendors act these days, which is using every avenue to maximize profits. There's no recourse, because it is proprietary and, therefore, belongs to the software maker, and not you. It is not your property, it is theirs.

Which leads into...

"If you're the customer, you're the product" because customers are valuable products. You willingly bought the service, so your data is data from someone who is interested in the company and probably willing to buy more from it and its partners if the company can target you. Your data, therefore, has resale value, making you a product to be sold.