These days I seem to be hearing more and more supposed subject experts on the radio whose sole qualification seems to that they are bloggers or podcasters. Quite often I'm unimpressed by their insight or mastery of the subject in question, or both. I hope they aren't selected simply because they are easy to find by going on the internet. I know when it comes to locating subject experts these folk are pretty low hanging fruit. Quick is cheap. But you get what you pay for.