Olive oil is a key part of my kitchen supplies. We cook with it, use it in salads, and use it in many recipes. Normally, I prefer extra virgin olive oil. Healthy for one; it has some taste to it.
However, there is also a role for extra light olive oil. For one thing, its lack of taste makes it palatable for people who may find extra virgin olive oil not to be to their taste. Second (and this is a bit exotic), this is one of the approaches to the so-called "Shangri-la" Diet. I tried that diet once, and lost about 10 pounds--and have kept most of that off since then (A long story, but the Atkins diet helped me shed 20 pounds, much of which came back--I tried Shangri-la to retain some of the gains from Atkins--and it worked!).
Anyhow, while I prefer Extra virgin olive oil (and I do like the Bertolli brand), this Extra light has a useful role to play.