Conversions are tracked like this:
Viewer sees video, we tag them with an e-tag, ip and cookie, and wait for them to convert.
We attribute that conversion back to their viewing of a specific video.
We would not show conversions from a viewer on a video they didn't watch. Or that they watched AFTER they converted.
A conversion window is how long after someone watches a video do you still want to track a conversion for that video. e.g. if a viewer watches a video and convert next week, you'll likely want to track that. If they convert next year - then no.
If you think your people will buy multiple times within your conversion window and you want to see those multiple conversions in your vid stats - set it to "every conversion".
If you sell a product that people buy only once (like a monthly subscription, that is purchased only once and active from then on), you can set your conversions to be counted only 1 per visitor.
If you need help understanding how conversions work or how to set them up on your website, contact us!