Below is what it looks like today. Basically there are only two engines driving all search: Google and Yahoo. They feed most other search engines for both organic and paid search.
(Image Soucre: Bruce Clay)
Now step back in time 10 years or so. There were 100’s of different search engines around.
(Image Source: Bruce Clay)
Ten years ago, one would hire a firm to submit their website to the different search portals for indexing purposes. Why because there were simply too many and the submission procedures too varied.
Today of course that is no longer an issue. You simply submit to Google and Yahoo and you are done – assuming Google lets you in!
Also of interest is the fact that 10 years ago or more there were no standards for the various search business models and how they worked. Search was still trying to define itself. For example, goto.com was a strong contender in organic search back then but you had to pay each time your listing (not an ad) was clicked on. You paid more to be higher in the organic search results. However, keep in mind that back then we did not really use the words organic or paid search.
To use this really fun and interactive relationship chart go to: http://www.bruceclay.com/serc_histogram/histogram.htm