Booking Segments can be set on a booking at the time a website request or reservation is made.
To do this the segments must first be set up inside your account (see more on Booking Segments).
Once setup you can then add the parameter &segment=yoursegment to your widget url. Bookings and enquiries will then be tracked with this segment.
How might this be used?
If using a widget on facebook you could track bookings and enquiries from the source by adding &segment=facebook to the url eg: bookings made via https://accomdemo.bookfast.jp/cw/gen/ins/bpay2.jsf?vid=2c9890f06b0fbfc6016b1ff786ca64ca&segment=facebook would be marked with the segment facebook.
If linking to a widget from a Mailchimp campaign you could track bookings and enquiries from the source by adding &segment=mailchimp to the url eg: bookings made via https://accomdemo.bookfast.jp/cw/gen/ins/bpay2.jsf?vid=2c9890f06b0fbfc6016b1ff786ca64ca&segment=mailchimp would be marked with the segment mailchimp.
You can also use this to track referrals from other websites by creating segments for each referrer inside your account and giving them a url containing this segment as parameter.