Originally Posted by
3timesalady
Book as early as possible, and make sure you consider EWR as a start-/ end-point, unless it is ridiculously inconvenient to get there, as oftentimes the ORD-EWR tickets were a little cheaper than ORD-LGA.
Note that of course the frequency on ORD-LGA is hourly or better whereas ORD-EWR is only every 2-3 hours so the capacity and ability to make changes is a bit more restricted.