By Anna Cebrian, owner of Isle of Gamers and Illusive Comics & Games

Just as forensic scientists know "every contact leaves a trace," every engagement with a person is an opportunity to market your business. All your interactions have a chance of reaching a wider audience through word of mouth.

But relying on word of mouth alone is a disservice to your business. Without support from other strategies, you're shooting yourself in the foot.

Why Word of Mouth is Not Enough

When you limit yourself to word of mouth, you limit your audience, your authorship of the message, and the value of your contacts.

Just look at the numbers. The number of people coming to your store is X. The number of people attending an event is Y. The number of people who are going to discuss that event with their friends is Z. These are smaller and smaller numbers—do you really want your marketing to rely on that fraction?

If you're relying on customers to share your message, not only are you unable to control who it's going out to—you're unable to control what the message is. Who do you want to be in control of the conversation? You or a handful of your customers? How about competitors?

And if you take ownership of the conversation, contacts become more valuable. For example, my staff ask every customer if they receive our newsletter. Subscribers are usually more valuable than non-subscribers, and while word of mouth is powerful, it won't drive people toward a newsletter.

That's the best approach: generate contacts, then support them.

If every contact leaves an impression, online and IRL, you need to both actively generate those contacts and have resources in place to support them.

Generating Contacts: Social Media

We focus on social media because it corrects all the shortcomings of word of mouth: we can easily control the audience, the reach, and the message. You're able to direct the age range, the city, the gender—you can really control the conversation.

Timing is key. Test the waters and see what works. Check the readership stats on social media and e-newsletter sites. For example, we found that sending the newsletter at the beginning of the week resulted in lower readership and preregistrations.

Supporting Contacts: Yelp and your Website

To support the contacts you generate, start with Yelp. At least here in the Bay Area, Yelp is a part of daily life. You don't get a haircut, you don't go eat somewhere, you don't even go to a park without checking Yelp. And Google just sends people there. Hate Yelp? That's fine. You still have to do it. Because Google.

Second, your website. If you only have a single page with no images, if your hours aren't listed in the top third of your homepage, if it's outdated or disorganized, potential customers will think that's reflective of your shop.

We use Weebly, but Wix and Squarespace are also great. For newsletters, Constant Contact or MailChimp are affordable on any budget and have customizable templates. I'm not a tech person, but I'm able to easily craft newsletters and manage my website by myself.

If there's just one thing you should do to start, it's this:

Look at your online presence with fresh eyes.

See it from the point of view of a brand new customer. Look at your website and start updating. Make sure your Google and Yelp pages are updated with the correct hours. Be posting online every day.

Otherwise, you're letting money walk out the door.

Anna Cebrian is the owner of an Advanced Plus location and an Eisner-nominated comic book shop. Before joining the industry, she earned an MBA in e-business from the University of Phoenix and a Bachelors in Art from Whittier College.