Too Long; Didn't Read
There are several different types of events that a host can attend or host to promote a podcast. Stickers are better than business cards and should only be brought to an event less than 50 at the start. A host should target a small group of people for a meetup. A larger meetup means less time for the host to get to know the people at the meetup. Have people sign in. Even if it's on a piece of paper, the host can get the attendee's emails.