The difference between mean and median provides information. It's always safe to assume the distribution is right-skewed, but having both median and mean gives you a sense for how much.
Just the difference doesn't tell you much. It's always right-skewed. But that could be because it's bimodal with developers earning a lot and support staff little or it's because everyone makes the same except for some really well paid executives.
What would be really interesting would be to see the actual distribution. But I don't think we'll ever see that.
I think at this point we're quibbling over the definition of "how much" it can tell you. I think "median of $70k, mean of $150k" vs. "median of $70k, mean of $1.5M" carries a lot more information than just mean or just median, even if it doesn't approach a full summary of the distribution's shape.
