Labelling for Venue Visit Detection by Matching Wi-Fi Hotspots with Businesses

User behaviour data is essential for modern companies, as it allows them to measure the impact of decisions they make and to gain new insights. A particular type of such data is user location trajectories, which can be clustered into Points of Interest, which, in turn, can be tied to certain venues (restaurants, schools, theaters, etc.). Machine learning is extensively utilized to detect and predict venue visits given the location data, but it requires a sufficient sample of labeled visits. Few Internet services provide a possibility to check-in for a user --- to send a signal that she is visiting a particular venue. However, for the majority of mobile applications it is unreasonable or far-fetched to introduce such a functionality for labeling purposes only. In this paper, we present a novel approach to label large quantities of location data as visits based on the following intuition: if a user is connected to a Wi-Fi hotspot of some venue, she is visiting the venue. Namely, we address the problem of matching Wi-Fi hotspots with venues by means of machine learning achieving 95% precision and 85% recall. The method has been deployed to production of one of the most popular global geo-based web services. We also release our dataset (that we utilize to develop the matching model) to facilitate research in this area.