Page Monitors - Information Trapping: Real-Time Research on the Web - page 45

Why use a page monitor?
here are two instances in which you'd want to use a page monitor:

. You need the content, but you can't get it via RSS. I already touched
on this in the introduction to this chapter—you may want to keep
up with a news source or with a page of information content, such as
press releases, for example, but the information isn't ofered via RSS.
In this case, you can use a page monitor on the appropriate pages.
Say you're monitoring the Events page of your favorite band. You want
to be updated when and where they're touring so that you're sure not
to miss them when they're in town. Or maybe you want to monitor
a page that contains information on a company's board of directors.
You want to see when information about that group changes, some-
thing that might be more diicult to do with an RSS feed.

When you need just a tiny bit of information . here may be some
data point that you're interested in that is too small to be the subject
of an RSS feed. You may want to know when a number changes, for
example, or when a date changes. In that case, monitoring the page
for changes makes more sense than trying to set up an RSS feed.
Just make sure you're not reinventing the wheel. If you're looking for
a common small bit of data, like a stock quote or a temperature, there
are services that can provide you with that information via e-mail
alerts. (I cover e-mail alerts in the next chapter.)

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types of page monitors
here are two kinds of page monitors:

Web-based. Some page monitors are Web services. You go to the site,
enter the pages you want to monitor, and receive page updates via
e-mail ( Figure 3.1 ).
hese services can be either free or fee-based. he advantage with
Web service page monitors is that you can access them anywhere and
receive the alerts on any device in which you are able to receive an
e-mail (including cell phone, PDA, and so forth). he downside is that
they're oten limited in their conigurability and sometimes show far
more false-positive alerts than you would like. hey'll also start cost-
ing you some serious money if you want to monitor more than a few
dozen pages at a time.

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