If the expert answers ‘no’, that may be OK. Follow up with something like ‘Oh, you’re using Posterous instead?’. If they look at you blankly, end the meeting there. No sense wasting your time.

If the expert answers ‘yes’, get the address and go look. If they’ve been blogging for less than 2-3 years, and there’s no explanation like “I had to move my blog”, again, end the meeting.

Any social media expert has been somehow participating in the conversation for a long time.