Technical perspective: Computing the value of location data

it aids in making its purchasing and business decisions. The introduction of these principles means both buyers and sellers can set fair prices for GPS data, which today is still largely given away for no cost. Establishing these prices is a first step toward building a geo-marketplace, where sellers can be fairly compensated, and buyers can determine which data is most valuable for their application. Geo-marketplaces, however, raise unique concerns. Publishing geo-tags reveal owners’ whereabouts, which may lead to serious privacy breaches such as leakage of one’s health status or political orientation. In addition, one must also protect the interests of buyers, and ensure they receive data objects satisfying their spatial requirements. Owners must be held accountable for their advertised data and not be able to change the geo-tag of an object after its initial advertisement. This can prevent situations where owners change geo-tags to reflect ongoing trends in buyers’ interest. For example, when a certain high-profile event occurs at a location, dishonest owners may attempt to change their geo-tags closer to that location in order to sell their images at higher prices. Furthermore, the system must provide strong disincentives to prevent spam behavior, where dishonest participants flood the system with fake advertisements. These are possible future work for geomarketplaces, some of which we discussed in a recent paper.