In the end Monster showed me 37 jobs ads. I pressed the RSS feed button and subscribed to the resulting feed in Google Reader.
Seven (7) ads.
Where were the other 30? I inquired on Monster's support line and "Roosevelt" explained that one receives only those postings that appear after one subscribes to the RSS feed. As a matter of fact, I don't think that this can be quite accurate as an explanation because some of the job ads in the feed were amongst those that I identified in the search. However, support lines are not the place to argue, are they? The real point is that it's important to make whatever use one can of all of the jobs in the search listing before beginning to rely on those in the Monster RSS feed.
Oh, and incidentally, the Job Bank seems to get it right. I'm making an RSS feed for my client for the Job Bank too, obviously. I noticed that the both the search and the corresponding RSS feed for him yielded 72 job ads. Nice.
(1) Why do most Big Boards fail to code jobs? It's not as if there aren't a number of perfectly good coding schemes. And, if they don't want to ask employers to use those then, why can't they incorporate some up-to-date natural language processing? Failing that, why encourage term-based searching for clients when even professional users of Boolean strings, like recruiters, find them a challenge?