We frequently talk to businesses and startups trying to decide whether they need to build a mobile app.

One of the first questions you must answer before creating a mobile experience for your customers is whether to use an iOS or Android app to do so, or whether a website that accounts for mobile devices is enough.

A mobile-friendly website (one that is responsive) has become a non-negotiable. Even if you have an app, some customers will use their smartphones to access your website. Google now measures mobile usability and factors it into search-engine algorithms; A responsive website is something every business must have.

Some businesses need an app as well. Does yours? These three questions will help you decide:

In general, it’s easier to capture revenue with an app than it is on the web, because you can sell the app in the App Store or Google Marketplace and offer in-app purchases. If you can get customers to buy, it will usually be easy for them to complete the purchase with an app.

You can sell ads both on a responsive website and on an app. If your revenue model is ad-driven, you’ll need to forecast how many impressions you’ll get from either platform, and how the advertising rates for mobile web vs. app compare.

If your revenue is gained through memberships or access, an app may become a key selling point or add-on that will lead to more members and better renewal rates. You’ll need to know your customers and market well to know how the cost/benefit ratio justifies an app build.

Your business needs to go mobile—but it doesn’t always need an app to do it. You need to choose a developer like Worthwhile who will help you decide how to go mobile in a way that will connect with your users.