While I think notes to remember who to follow-up with are good. I am actually a bit put-off when someone emails me on the spot. That email contains no value, ex

While I think notes to remember who to follow-up with are good. I am actually a bit put-off when someone emails me on the spot. That email contains no value, except contact info, and pretty much puts the onus on me to create the follow-up conversation. It also makes me feel like you think you'll forget me the minute you walk away, so you better do this now before you move on to your next target. My recommendation would be to follow-up after the event, with an email that provides some additional context and shows me you are still interested, that it wasn't just an impulse thing.