Once is an online dating platform based in Switzerland that was launched in October 2015. Founded by Jean Meyer and his colleagues, it was introduced as the "slow dating app" that works by providing you only one single match per day. They call this "personalized matchmaking" as they believe that quality is a better way of finding your match versus quantity.
Their personalized matchmaking does not involve a machine or a system that does the matching. They actually have a team of matchmakers that matches members based on the information on each profile. Likewise, proximity and the number of active members for the last 48 hours are big factors when they do the matching.
Once you have been selected for another member, you shall have 24 hours to enjoy the company of each other. You can send a one-time message to your match using a token they call "crowns" and if he or she replies, a chat screen will be provided where you can talk for as long as you want.