Responsive web design may seem easier because you only have one website, however it is not always easier for your users. A native app is specifically developed for a mobile device, users download the app and install it on their mobile device.
The most convenient thing about native apps is that they are flexible and not only let you have the same stuff that is on a desktop, but also provides mobile specific features like a click-to-call button, GPS or contact/gallery access. An native app is immediately and easily accessible, its visibility icon encourages users visit more often.
Building a native app for you business helps you address the exact needs of your customers in a more effective way and can help increase you revenue. There are a few ways this can be achieved. First of all you can charge users to download your app, also certain limited features could cost extra. A small fee would be worth it to your loyal customers. Another way to earn money is in-app advertising, you let users download your app for free, however display a third party adds and earn through PPC networks. A native app is an investment, however, the returns are significant.
If possible, building both a native app and a responsive web design would be optimal. The native app would provide a mobile centric experience for existing and loyal customers, while the responsive website provides an optimized experienced for both new and old visitors exploring the website for the first time.