Circulation
An approximate measure of the number of individuals for whom your feed has been requested in the last 24 hours. Circulation is inferred from an analysis of the many different feed readers and aggregators that retrieve this feed daily. Circulation is not computed for browsers and bots that access your feed.
Circulation is calculated by matching IP address and news reader combinations, and then using our detailed understanding of the multitude of readers and aggregators and bots on the market to make additional inferences.
Hits
The exact number of requests for your FeedBurner feed during a chosen summary period. Hits are a raw measure of the amount of traffic your feed is receiving from all sources.
Dus circulation zal een stuk dichter zitten bij hoevaak het met iTunes is binnengehaald. Dat zegt natuurlijk nog niets over of er wel naar is geluisterd, hoelang en met hoeveel plezier...