I take a lot of meetings to just try to be helpful, especially with people's careers. Other times, I'll take a very early meeting with an entrepreneur throwing around a few ideas or someone who comes to me when things just aren't working. I feel like I give pretty decent advice--and that's just purely based on the excitement of the person when they walk out of the meeting.
Yet, I probably never hear back from 85% of these people. I have no idea whether or not they ever put any of these ideas into practice, whether they worked, or whether they failed miserably--which would be good data for me.
I noticed this yesterday when two entrepreneurs that I really like came in for the second time, about 3-4 weeks after our first meeting. We had a good chat the first time, I made some intros and suggestions for them. They followed up on all the intros and let me know that they did--which was great b/c I hate when intros disappear into the void (Hashable solves this when people click on the follow up note). They also told me that some of the suggestions that I gave them didn't work at all--good to know. It was a very productive meeting that helped me work on next steps with them.
When someone doesn't follow up at all on advice--even to tell me that the advice turned out to be terrible and not work at all--it really makes me regret even spending any time at all with the person. I assume they walked out the door, never took any of it, and just went on their merry way. That would be a real waste of everyone's time.
Here's a suggested way to follow up:
1) If you requested the meeting with me, it's your job to provide the thank you e-mail--and that should include a summary. "Hey Charlie, thanks for meeting. Your suggestions to do x, y, and z were really appreciated and I'll definitely keep you posted on how stuff goes. I may not be able to get to them until December, but when I start, I'll let you know."
2) If you execute or run into trouble with specific suggestions, follow up questions are always welcome. Same goes when you accomplish a specific task that was a suggestion--a post mortem on its success or failure would be great.
That's all I'm asking for--just let me know if any of the time we spent together turned out to be useful, not just because we had a good chat, but that it was actually impactful in some way.