Used in a dismissive way when you're out of things to say in a discussion and/or are bored with the topic. In actuality it means nothing, but for a few seconds it sounds like it means something profound, which gives you enough time to switch topics to something you know more about.
Jill: Marijuana should be legalized, the government could make so much money if it were legal, because they could tax it instead of waisting money housing pot users who are in jail.
Jack: That's only as true as it is false. Anyways, did you hear that Johnny got fired from his job?