I believe they do use their own ad platform. But I would guess that the pricing of ads on Facebook and Google mean that even if they could charge a premium, it

I believe they do use their own ad platform. But I would guess that the pricing of ads on Facebook and Google mean that even if they could charge a premium, it wouldn't be enough to sustain the business. There is only so much of a premium you can charge before no is willing to pay for your product.