<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by gleff:
This not only gets you the extra segment credit (or the "right" number of segment credits), but also makes it easier to nab upgrades. Remember that if you have booked both flights as a single direct flight, upgrade availability needs to exist on both segments or you won't have access to the seat. However, if you book two separate flight segments, you can get the upgrade on one and wait list the other.
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Another reason why upgrades are easier is as follows:
Say we are talking about UA's (extinct) flight 1 from LHR-IAD-LAX. Booked as a direct flight, the exact same seat need to be available all the way through. If from LHR-IAD seat 15 is available, but from IAD-LAX 15a is occupied, 15a will then show occupied on the seat map for the entier journey (when booked as a direct flight). But booking segment by segment, more options will be available.
I have been denied upgrades because of this, yet when I split the ticket into two segments, the upgrades become wide open.