A FAST channel earns from impressions, and an impression is counted by the server that stitched the ad into the stream. That server belongs to whoever hands the playlist to the player. If your channel runs on your own playout and your own delivery, the count is yours, and a distributor who carries the channel gets a share from a report you produce. If a provider takes your files or your feed and serves the channel from its own systems, the count is theirs, and you are paid from a report only they can produce. There is no arrangement in which both sides measure independently, which is why this is a contract term and not a technical detail.
Neither answer is wrong. A rights holder with two thousand hours of drama and no interest in running anything is well served by handing the stream over and taking a share. A community broadcaster, a sports club or a creator with an audience of their own usually wants the channel to stay theirs: the stream URL, the guide, the cues, the analytics, and the whole of the ad revenue. Which one you are decides which providers to talk to, and the seven questions above are how you find out which kind each one is. If the open question is whether you want to operate the channel at all, managed playout vs self-serve is the page for that.
Our own answers, for the record: you serve the manifest, on your own account, from $254 per channel per month with delivery included; there is no content minimum; the files, the grid, the guide feed and the cue configuration are yours to export; both SCTE-35 command forms are emitted with a cue profile per partner; the guide publishes as XMLTV, JSON and a web page up to 14 days ahead; and the channel watches itself for encoder restarts, dropped feeds and frozen picture, falls back to a standby screen, and tells you. The distribution dashboard then treats aggregators and platforms as what they are: carriage partners you can add or drop.