Measuring RSS activity in Apache log files

We have a number of in-house publications that are produced both as 
static html and as xml for RSS readers. I'm trying to get a better 
understanding of what the hits counts in my Apache logs really mean with 
respect to the xml files.

Do RSS readers actually fetch the xml file repeatedly and thus show up 
in the log with an "artificially" high hit count? Or do they just 
compare the date & time stamp they currently have and only fetch the 
file when they're out of synch? (I should probably clarify that these 
particular rss feeds never output individual items incrementally, but 
only get refreshed when an entirely new issue of the publication comes out).

Thanks in advance.

Bobb Menk
MIT Lincoln Laboratory Library
_______________________________________________
Web4lib mailing list
Web4lib@...
http://lists.webjunction.org/web4lib/