I have found there are 5 types of people who will visit your poster at SFN.
People you already know AKA the fan club.
Do not underestimate their power. Not only do they save you from boredom, but occasionally they get other people to stop because they want to see what the excitement Is about (see 4).
People who know one of the other authors on your paper.
These people wanted to see an old friend, or meet your PI. They will most likely be disappointed to find out they can only meet you. Or be more excited to meet your PI then anything you have to present. They will stay long enough to be polite, so at least you get to present some of your data.
People who thought they were interested in your poster but weren’t.
We’ve all been on both sides of this, They scanned your title, your abstract came up on a general search, but upon arrival it turns out it in no way helps. They will (usually) also attempt to be polite, but will be obviously disappointed.
People who got distracted by your poster
This is the person who was walking by and happened to see your poster. maybe you had a catchy title, maybe they wanted to join the crowd, or maybe you made eye contact and they got sucked in. Interesting discussions typically follow, though not always helpful.
People actually interested in your poster.
This is what we all dream of. Someone interested in your work! Your poster mattered to someone! If you are one of the lucky people to have this visitor cherish it.
Good luck in presenting at future conferences. Here’s to hoping for lots of #5 visits!