"Dynamically Inserted Ads
In recent years, ad technology has allowed for ads to
be targeted and dynamically inserted at
the time of file request. The
ad
server determines the best ad to serve to the listener at the time
of request. In a podcast consumed online, ads may be inserted into a file that is being
progressively downloaded
at designated ad breaks
. Some
publishers
may count this dynamic
ad serve
as an "impression"
without confirming ad delivery. T
he metrics in this document focus
on confirming that the ad was delivered. S
erver log
s can
confirm that the
enti
r
e
ad
file was
downloaded
, but the process for counting a served ad can
only determine that ad file was sent
."