One of the two billing models in MapTiler Cloud is based on the number of generated tile requests.
This way the customer pays only for what they use. A single vector map view usually generates 4 tile requests. The raster map view (using 256px tile size) generates 10-16 requests. Please take a look at the requests counting demo here.
Requests counting table
|TileJSONs, Style JSONs, Fonts, Viewers, XMLs||Free|
|Rendered raster 512x512px tile including HiDPI/retina||4|
|Rendered raster 256x256px tile including HiDPI/retina||1|
|Single tile served from .mbtiles||1|
|Static maps API image||15|
|Vector data (GeoJSON)||1|