I was the only person there.
The event coordinator took money out of the till and took the two of us to the restaurant next door, where we had a nice chat, beer, and desert. Afterward, I bought a book.
Go to signings. You don’t even need to buy a book, although that’s always nice. Go to signings and ask questions that aren’t just “Can you give me the name of your agent?” I know a mystery fan who shows up at everyone’s signing, even if it is their first book. Because of this, he now counts Michael Connolly and pretty much every other big name as a friend. So for purely selfish reasons, go! You can name drop when they get famous later. You can forge friendships that will stand you in good stead. You can get a peek into someone else's mind and process. And you can also make a lonely author’s day. I’ve seen big names on tour when there were more people in their entourage than there were in the audience.