Of course they paid for it... Do you really think the Mozilla Corporation has sent an ad to millions of users for free? Whether that money went to the corporation or to the pocket of an executive, that's another matter.
Or it can be a deal to see what returns the ad gets. If Mozilla is serious about selling ad space there, they're going to need case studies. In the early stages, that is something you would give away for free. Particularly because the ad providers are going to get a lot less data than they are accustomed to, you will need some case studies that show someone getting great returns on their ad spend even without tracking data.
Then the statement "It was not a paid placement or advertisement." is blatantly false. they simply say whether it was paid, not whether it was paid to a specific entity.
> This snippet was an experiment to provide more value to Firefox users through offers provided by a partner. It was not a paid placement or advertisement. We are continually looking for more ways to say thanks for using Firefox. In a similar vein, earlier this month we offered Firefox users a free opportunity to enjoy a live concert from Phosphorescent.
It could be that they are knowingly making public statements which are untrue and will expose themselves to legal liability for that or it could be that the statement means exactly what it says and that Mozilla is experimenting with promotions for using Firefox which do not involve money changing hands, especially if they're just gauging interest to see whether people even click on those regions. The concert was definitely promoted as a “Thanks for using Firefox” deal so I would not be at all surprised to learn that Booking.com gave a modest discount as part of a deal where no money changed hands as per the statement.
> This snippet was an experiment to provide more value to Firefox users through offers provided by a partner. It was not a paid placement or advertisement.
I don't know about legal liability, but you don't really need to look further than this to know that Mozilla lied because these two statements are already inconsistent. "Offers provided by a partner" are advertisements. The quid pro quo in this case wasn't money, but rather a link on booking.com to download Firefox.
