There should be no question as to the most influential personality at South by Southwest (SXSW) Interactive this year. There's only one entity that had people lining up for three hours just to take photos with her, hold her, and perhaps rub her sweet little head. Grumpy Cat, the alias for a Snowshoe Siamese named Tardar Sauce that became an internet meme thanks to Reddit, has captivated the masses tracking and attending this festival.

Clearly this cat is on to something. Is Grumpy Cat's popularity at SXSW just another indicator of the internet's obsession with cats? No, this is something much, much bigger than a tiny, adorable, peevish cat. Here's the Grumpy Cat guide to SXSW:

1) SXSW is a festival for memes. Pundits and attendees looking to find the next big thing are really looking for memes. In years past, Twitter, Foursquare, and GroupMe were all memes that successfully spread within the SXSW community and then far beyond. Great speakers are memes too; this year, Tesla Motors CEO Elon Musk was the biggest meme among keynote speakers, albeit a meme with one-twelfth the search volume in Google as Grumpy Cat over the past week. Great food and parties are memes too. Memes are bits of cultural information that spread, and what makes SXSW attendees unusual is that they constantly seek out these memes and spread them further.

2) Brands can be memes too. In 2012, Nike's FuelBand became a product meme. While the product couldn't be shared easily, the experience transferred among attendees in a very salient way. Memes don't always spread quite that widely. This year, in the Convention Center exhibit hall, I picked up a $30 gadget called the Palm Top Theater which encases the iPhone to turn it into a 3D video player. I carried it around in my pocket all day, and I showed it to most people I met. On a smaller scale, that became a meme. Memes aren't just about products though. BBC America combined Texan and British icons and created a mechanical bulldog that partygoers could ride. The bulldog became a meme, something people couldn't stop talking about. People like me who rode the bulldog shared photos, videos, Vines, and GIFs of it widely. For years, people will talk about what it was like riding the mechanical bulldog at SXSW. A meme is born.

3) Memes don't just live in the digital world. Grumpy Cat is a real cat – a cat that wouldn't be very famous without Reddit. People don't just experience Grumpy Cat online though. In becoming a part of culture, people will refer to anyone scowling as being a Grumpy Cat. It's a brand with emotional resonance. There's no such thing as a purely digital brand. When Twitter and other software companies broke through at prior SXSW festivals, it was because they built brands that became memes.

4) People want the one unforgettable experience. Why did people wait in line for three hours to see Grumpy Cat? Because everyone else was waiting in line. When I visited installations in the Convention Center from Oreo, HBO's Game of Thrones, and The New York Times, they looked more fun when the lines were longer. While FOMO ("fear of missing out") is a tired buzzword by now, at SXSW it's a persistent phenomenon, where every decision to attend something is usually a decision not to attend several other compelling options. Despite the fear, people gravitate toward what they think will be most memorable, and most social. I've held quite a few cats, but only at SXSW did I tell everyone I met that I took a photo holding one; it was by far the most liked SXSW photo that I posted on Facebook too.

5) Marketers capitalize on memes. Before SXSW began, Friskies tapped Grumpy Cat to star in a new campaign. Usually it's not quite that literal though. When brands resonate with consumers, it's often because they know what motivates their consumers to spread those ideas – or memes – with others.

2013 was the year memes came alive at SXSW. Memes have always been part of the festival though, and they always will be. The best brands are among the most successful memes ever created. Marketers will keep coming to SXSW as long as memes stay central to the experience. That means there's even more to see at SXSW than Grumpy Cat. She's okay with that though; Grumpy Cat didn't seem thrilled to be there anyway.