[OhHeyItsE]

Hypothetical: individual pricing based on how likely you are to pay more for an item, or how badly they think you need it. Sharing of data across domains could place you in a "bubble" where you see the same price no matter where you look.

[kabacha]

That's exactly what a lot of airline websites do. If you're an active user of one try firing up a clean instance of different browser and it's very likely you'll see a different price.

For products that can benefit from information asymmetry[1] fingerprints are an amazing tool.

1 - https://en.wikipedia.org/wiki/Information_asymmetry