The HTTP with keyword monitor works in a similar way to the basic HTTP monitor but with the addition of a keyword scan. What this means is that ServerMojo fetches the page at the url you specify and then searches for the keyword or phrase you enter. If the keyword is found then the site is considered to be online, if the keyword is not found then it is flagged as offline. This test is a much more accurate test for a web site and can be used to check that your site, even a dynamic database driven site, really is online and functioning correctly.
You can also use this type of monitor to check a whole range of other systems with some minor custom code on your side. For example to check a database is functioning properly you could create a simple script which does a select and creates a basic web page showing some text pulled from your db or even db status messages could be displayed. Then you simply create a ServerMojo monitor and enter the text to scan for in the usual way. An even more advanced version of this is the HTTP Value Extract monitor which allows for full regex extraction.