You’ve got an event coming up, and you want to fill every seat. How do you throw a champagne event on a beer budget? With social media! Here’s how: Have a unique, event-specific hashtag. The key here is to research it first. You need to make sure it hasn’t been used before or associated with something negative. Encourage attendees to tell the world they’re going. After they register include a “share on Facebook” button. Or write a tweet for them — with a call to action, like