As Instagram continues to soar in popularity, more companies are trying to find ways to use their accounts as a way to amass fans. Interior design startup Homepolish is one company that has mastered the formula. Homepolish, which acts as a middleman between customers and designers, has gained more than 840,000 followers since its launch in late 2012 with its feed of beautifully designed and decorated rooms. In fact, the New York-based startup says it attracts about 2,000 new followers every day.

Homepolish founder Noa Santos and product manager Kate Haberbusch spoke to Inc. about how to use Instagram as a marketing tool--and turn some of the app's 400 million monthly users into potential customers.

1. Craft each post to appeal to several different emotions. 

As a rule, Homepolish makes sure each post connects with users in at least two different ways, which it believes doubles the chances they'll share it with others. Haberbusch says that a viewer might tag someone in a post because it offers design inspiration, has a "cool factor," shows something unique, or just looks gorgeous. The post at right features a wall painted with the lyrics of Edward Sharpe and the Magnetic Zeros' love song "Home." Users might tag others because the photo depicts an awesome design--or as a way of showing a loved one they're thinking of them. The recipe worked: The post has 554 comments--the most of any Homepolish post--and most of the comments tag one or more other Instagram users.

2. Give credit where it's due. 

Homepolish uses the photo caption to tag the photographer as well as the interior designer responsible for each post. Santos knows this means the company is opening the door to having potential customers cut out the middleman and contacting designers behind its back. "I am 100 percent certain that happens," says Santos. But the company believes in building good karma: "The couple of clients that slip through the cracks," he says, "are worth you being authentic as a brand." 

3. Don't assume you know what works. 

Early on, Homepolish occasionally featured people in its photos of living spaces as a way of livening up its feed. When they analyzed likes and shares, they discovered those photos received significantly fewer social interactions than the rest. "We realized that people want to insert themselves into the scene," Santos says. "They're not coming to us looking for photos of other people." Since that revelation, Homepolish's feed has become entirely human-free.

4. Be consistent. 

Homepolish posts twice per day, a number it settled on after careful analysis. Santos believes this keeps users satisfied without oversaturating their feeds. The company's target demographic is people in their 30s, which means they're likely to have 9-to-5 jobs. So the company posts one photo before lunch and one after dinner, when people are most likely to have some down time and check their phone. The time of day doesn't vary much--nor does the nature of the content. "Regularity is really key," Santos says. "We know that people want to see great shots of spaces. They want to see shots that are beautiful, and accessible, and speak to who they are as an audience--and they want to see approximately two posts per day. From that strategy, we don't vary."