Placing small postcard size info sheets around the conference (bathrooms, hotel lobby, conference tables, conference seating areas).
Another hack is find the list of attendees and reaching out to them via email saying you're sorry you missed them at the event, but you'd love to set up time to chat.
Some conferences would sell the list of attendees .. it’s not advertised but if you hustle you may be able to get it
Did this at JP Morgan healthcare conference. Agree w/ the list of attendees, but you can be successful even without the list. Just target folks who _might_ be there, with a subject like “{name} - meet at {conference_name}?“. We had a ~5% conversion to meetings - sent out 250 emails using Mixmax. Got many folks saying they wouldn’t be there but would want to schedule a call instead. Doesn’t hurt to cast the net super wide. https://intercom.help/alchemistacc/en/articles/3079210-what-are-your-thoughts-on-conferences-and-related-networking-events