In order to determine which advertising and marketing efforts are effective you must have ways to measure the results of those efforts. Alerts and instant notifications can be instrumental in monitoring search engine position, trademarked terms, monitoring competitors and staying abreast of online occurrences. And, of course, the notification can be used for "ego searches".

Ego Searches
What is an ego search? Find out where your name or company is mentioned, view forum posts or online articles that mention your name or company.

Trademarks
The best offense is a good defense. By monitoring newsgroups or search engines for trademarked terms, you often head off a future conflict. As a trademark owner, it is your responsibility to actively protect your mark. Otherwise, you could lose your trademark rights. Monitoring tools send immediate notification should any suspected trademark infringements occur.

Search Position
Statistics show that more than 85% of Internet users find web sites with the help of the search engines. Therefore, a website's search engine position is crucial to its success. Prudent webmasters regularly check their search engine position. Monitoring fluctuations and re-indexing of major search engines affects keyword terms and phrases. Monitoring of positions will alert webmasters to any shifts before sales decline.

Competitor Watch
Monitoring newsgroups for mentions of competitors may allow you opportunities to chime in and offer an alternative solution in a helpful, friendly way. Knowing exactly what your online competitors are doing provides a competitive edge that can be used to your advantage.

Website Downtime
Accessibility is the most critical measure of your website's performance. If customers can't access your site, they can't shop; and if they can't shop, they can't buy. More important, your business could gain a bad reputation among your customers, which translates into negative word of mouth and even worse, if you're highly visible, negative press. So regardless of what else you monitor, you want to monitor websites for downtime.

Take a look at the various tools available and how they can be used to keep you current on relevant issues.

WebAlerts - Recieve email updates of the latest relevant Google results based on your choice of query or topic. Alerts can be sent based on information in Google News, Google Searches or both.
http://www.google.com/webalerts

PubSub - PubSub matches your requests against new information as it appears real time. Searches can be categorized to search, blog entries, SEC/EDGAR Filings, press releases, news group posts or flight delays.
http://www.pubsub.com

Ego Alerts - Google news search turned into an RSS feed.
http://www.justinpfister.com/gnewsfeed.php

Ebay Alerts - Ebay Alerts monitoring will create an RSS feed to monitor Ebay auctions for specific keywords or phrases. When a new item that contains those keywords is added to Ebay you will receive notification via your RSS feed!
http://www.freebiddingtools.com

Amazon Alerts - Generate a URL which you can use to automatically search Amazon.com with your favorite RSS news reader. It will automatically update you when new items meet your search criteria. I personally use it to look for new books on topics I'm interested in, and I have the defaults set to do the same, but you can adjust it to search any of Amazon's stores. You can also adjust the search order and what kind of items you wish to search.
http://www.oxus.net/amazon

Internet Seer - InternetSeer remotely monitors your website to insure that your site is available 24/7. If InternetSeer is unable to reach your site, we will send you an immediate e-mail alert that your site is unreachable.
http://www.internetseer.com

NetNewsTracker - NetNews Tracker is a clipping service for Usenet newsgroups. Newstracker searches newsgroups twice daily for any specified words or phrases and delivers alerts via e-mail. Newstracker can be used to monitor newsgroups for names, company names, products, URLs, or any other topic of interest.
http://www.netnewstracker.com

Other Suggested Resources
Monitoring Tools - Monitoring Tools is a directory of online monitoring tools and applications
http://www.monitoring-tools.net

Monitoring Software - Monitoring Software is a collection of downloadable monitoring software solutions.
http://www.monitoring-software.net