Yes.  First impressions matter.  Alot.  But, I argue that sincere follow-up matters more. Why? Because if you don’t follow-up, you are forgotten as soon as you move on from the conversation. Why spend all that time attending networking events, meeting new people and gathering their business cards if you aren’t going to take a few minutes to remind them that you exist afterwards?  What are the best ways to followup?  In my opinion, any follow-up method will do it as long as you are genuine and prompt.  Here are a few options to try:

• Email.  When you get back to your office, add the business cards you collected into your contacts (with a note as to where you met and what conversation you had) and then fire off a few emails to the folks you met.  Just a quick note to say that you were glad you met, comment on a conversation you had and then invite them to keep in touch.
• Social Media.  Look up each individual and their companies on Linked In, Twitter and Facebook. Follow them on Twitter, Like their company pages and invite them to become part of your network.  Send them a direct message telling them how glad you were to meet them and offer your services if they ever find the need.
• Phone Call.  If you had a particularly nice discussion with someone, give them a quick call and add something to the conversation you already had.  Invite them to lunch or for coffee to get to know them more.
• Written Note.  Yes, this is a bit old school, but it is a nice touch.  If you feel like you particularly connected to someone, take a moment to write them a note and invite them to attend the next event with you or grab lunch sometime.

It really doesn’t matter how you choose to follow-up, but it does matter that you take the time to do so.  If you can’t do it immediately, put a reminder in your calendar for the next day to do it.  Just make sure you do it within three days so that the memories are fresh and the sentiment genuine.  Once you have completed this follow-up, keep note of who responds and put a reminder in your calendar to follow-up again in a few weeks.  Your secondary follow-up could include an invitation to attend an event together, have lunch or coffee, company news (yours or theirs), or simply to connect on the topics you spoke about when you met.  It takes time and effort to build relationships, and it all starts with the right follow-up.