Networking is like a first date - don't try to sleep with me on the first date!
Networking is like going on a first date. Problem is, sooo many people try to sleep with you on the first date.
What do I mean? They feign interest because it's the "thing to do" - when they're really scoping out targets for their own selfish intent. For example, trying to get you to buy into whatever they're selling.
The next day, you get an email that is all sales and no attempt to build a relationship. Best case, you get a reference or two to your conversation the day before. Worst case, it's a cut-and-paste email detailing all their benefits and how they want you to come in for a "free consultation".
There's nothing wrong with reiterating what you do to stay top-of-mind, especially when your intent is to add value to that person. But don't try to oversell someone you JUST met. There is a trust factor there. People do business with people.
By trying to sell right away, you're making it clear you're only really interested in capturing people for your own selfish intent. It's short-term behavior.
I'll say it again - when networking, don't try to sleep with people on the first date!!