Pay-to-pick seating trickery

Q. I am flying United this week and just checked in online. I was forced to buy an "Economy Plus" seat with extra legroom because there were no remaining seats in regular economy. This is the second time this has happened to me with United, but it has never happened with other airlines. I fly nearly every week and I am about to cross United off my list of airlines. Is there any way around this in the future if I have to fly United?

A. This is a growing problem not just with United but also with other airlines, such as US Airways, that sell "premium economy" seats for an extra fee. One method is to not choose a seat assignment when checking in online. You'll probably get the extra legroom seat for free, but you won't be able to choose your exact seat location, meaning that you might end up in a middle seat. But you'll avoid the extra fee.