Google's Preeminence

When the Web was younger, the search engine field was all but wide open. There were lots of major search engines, including: AltaVista, Excite, HotBot, and Webcrawler. This proliferation of search engines had both its advantages and disadvantages. One disadvantage was that you had to make sure you had submitted to several different places. One advantage was that you had several inflows of search engine spawned trafffic.

As the number of search engines dwindle, Google's index (and influence) is growing. You don't have to worry so much about submitting to different places, but you have to be aware of Google at all times.