And even if you can tell what the product is, it‘s still often you. “Premium” subscriptions for example might hide (some) ads, but services still collect as much data about you. Even grocery stores where the offer seems obvious are trying to bait you into installing their apps to collect data on top of charging you for every item. And sure it’s not relevant in this case, but it’s something we should never forget.
Yeah, I feel like that's usually a very accurate saying, but it doesn't really work with a lot of open source projects.
I hate that you're getting downvoted by so many people who don't realize you're pointing out an exception to the rule, and instead think you have some fundamental misunderstanding about how Linux works.
They are getting downvoted for misconstruing something that is clearly a rule about profit making services and applying it to crowd sourced non-profit open source projects.
misconstruing something that is clearly a rule about profit making services
To be honest I don't think that's clear at all, it feels like it's more a rule about being skeptical of free stuff online. And many for profit companies have open source projects that can be used safely even though the source is a for-profit.
I think the issue was with the original commenter's phrasing. Facebook looks like a product. But the commenter meant "How the product is being funded".
Of course, it gets hard when there's multiple sources of revenue. You used to be able to spot ads and come to the conclusion that that was everything. Now an ad is just the tip of the iceberg.
The key difference is linux wants you to help make it better. Something like Honey steals your data, and steals money from others, and then wants you to make it better.