And what are these “pseudononymous” identifiers that you worry about? It’s much easier to track across the web than apps.

And how is installing the Hilton app going to allow another app to find out information about you?

Web/apps have a lot of pseudonymous data points but rarely have a link to your real-life identity. Real-life things like hotels have the latter but rarely the former. Installing an app allows data brokers to bridge the two identities.

> And how is installing the Hilton app going to allow another app to find out information about you?

Both apps rat out whatever they have on you to a data broker which then does the matching.