I am in the process of partnering up with some folks that have a web based platform that is gaining some traction. With this in mind, I was wondering if for an online platform that fosters user interactions there is a big negative impact from not having a mobile experience in place.
Do you think successful dating sites or social networks owe part of their success to their mobile experience execution? Thanks for your answers!
Your question doesn't have a correct or straight answer. So, maybe. :-P
A mobile app is not mandatory, however a mobile presence is. You must have your website deployed in responsive mode, so it supports mobile devices. The previous doesn't mean it is a mobile app. Similar things, however different.
Long history short, first make your website/platform responsive and then -maybe- make a mobile app from it. You can do the reverse, however launching a mobile app first is far more costly than doing a website first.
Best of lucks!