You're the product when you're in the middle of a marketplace. That's the one case where you, not something of yours, is on sale.

It is very good to know what of yours a company has that can be monetized. For a proxy, browsing data is straightforward. They have it regardless of how much you pay them. It doesn't stop being product just because they also happen to sell proxy services, just that if they make enough money selling proxy services they don't have to sell it to stay afloat.

The false dillema presented by "paying or product" is another good reason to use the phrase. If you are paying the company you are merely aware of one of the products they sell.

> it's safer to assume that I'm the product in each and every case, than to give my trust to someone I don't know a bit and to rely on "facts" a corporation is providing me.

Is paying someone to not sell your info not trust?

My bottom line with proxies is that they simply aren't a privacy tool. They can help but shouldn't be relied upon. Trying to figure out what the product is just obacures that proxies by their very nature have a lot of info on you.