CirculationData.apply passes analytics events on to an Analytics object if one is passed in as part of the ReplacementPolicy. If no Analytics object is passed in, there's code to instantiate the default Analytics object from database configuration, but the default Analytics object is not actually used.

The end result is that analytics events that happen on the vendor side (as opposed to within the circulation manager) are not counted. This happens with the Overdrive API and possibly others as well.