https://medium.com/@timberners_lee/marking-the-webs-35th-birthday-an-open-letter-ebb410cc7d42
Sir Tim Berners-Lee’s open letter to mark the occasion of the Web’s 35th Birthday.
@General_Effort@lemmy.world it's about retaining a single identity for yourself, and one which you control and link to where you are using it vs a unique profile at every different social network.
As far as I understand, you'd store eg tracking data in the POD. That would allow apps/services to give you better recommendations or personalized ads. The only party with any interest in writing to the POD is the end-user, but their interest is tiny. Better recommendations, so what? Advertisers prefer to keep their data private to have an edge over the competition.