Originally Posted by
ncorman
In reservation systems a non-stop will show first, a direct second and connecting third. Direct flights have been used on routes to try to show earlier in the results in GDS. Less of a factor now, but that was a huge concern in the past.
I believe they also show first when using some searches because they are not subject to additional taxes/fees that apply per segment.
So when flight results are sorted by price, they appear higher in the list than a connecting flight with the same base fare.