From OpenCellID wiki
Commercial users of the community servers
|According to the community server usage policy, you are not allowed to use the OpenCellID commuity servers for commercial applications without contributing data to the OpenCellID database at the same time.
Users with such requirements should instead sign up with one of the providers of commercial services based on the OpenCellID data. Another option you have is downloading the database itself here on a regular basis free of charge. (OpenCelliD Project by Unwired Labs is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License)
For more info, reach out at hello[@]opencellid.org