I'm creating several RSS feeds from a database to publish things like job openings, volunteer opportunities, and links in general. My question is, how many items should be returned in the feed so that it is most likely that someone will get all the items in their reader without any gaps?
SELECT TOP 100 ? (obviously would need to be set for # of feeds estimated over X time)
SELECT the last 24, 48, 72 hours?
If I run my feed through Feedburner, does anyone know if they check on a certain interval so that I can create it to their standard and be assured that the Feedburner feed will contain all items?
I personally would try to keep it to something under 25 or so. I know that the number of people using iGoogle for RSS feed viewing is going up, and there is a max display limit of 9 entries there. Many other RSS feed displays are limiting at 10-15 entries.
I find that an RSS feed, unless it is specifically an "all encompassing" feed by nature, is usually a small, quick-hit, update of what is going on or what is available.
As madlep mentioned i would also be careful to keep the size down.