[hnha]

I would guess that they do it similarly to private trackers. Each user gets a unique and secret ID which is transmitted when announcing. The tracker then decides if the user is allowed to get the swarm details.

[scott_karana]

Yup. I suspect it's exactly this, branded and hosted by Bittorrent Inc as a paid product.

[aidos]

Does that have the same benefits in terms of distributing the sources?

I just purchased the new Thom Yorke album [0] via a bundle and it felt like a regular torrent. Very quick to download etc.

[0] https://bundles.bittorrent.com/bundles/d0b4beba8efc4b46f6dba...

[spindritf]

See what kind of announce URL is included in the .torrent. Is it just

    udp://tracker.publicbt.com:80/announce

or does it include information that could be used to identify you, like

    http://tracker.bittorrentbundle.net:3000/3pr4s5y7l9nh0mdwcqyh3a9k6n7d0kta/announce

Other than tracker identifying you, seeding and downloading works the same in both cases.