To have a hierarchy of search engines it would help if
small engines could easily submit their database information 'upstream' to bigger search engines.
- reduce the load on big engines from gathering information
- provide for a more cooperative approach in information gathering
If I want my servers' or networks' information to be seen by search engines then I am responsible to participate by running a local search engine and have it /push/ its index upstream.
So in effect I do no longer submit urls to search engines but preprocessed data.