Why do personal site search engines suck?

[Skoonk]

A lot of work goes into designing a search engine like Google, Bing or Yahoo!. Unfortunately, the high expectations set by these products trickles down into all websites working as well as these search engines.

Providing some insight, a site's search engine typically only looks through their own database. Several things that make it difficult to deliver quality results:

1) Ranking - How do you rank pages for quality or relevance when it's on their own site? Google and others base their results on how often a page is linked to by other sites as well as how other users rate the page based on their search and browsing habits.

2) Keywords - Most site searches only look for words you type. What if you type "children" instead of "kids"? Google and others know how to deal with synonyms.

3) Speed - Most personal sites don't run on such power computers as Google and others, which consume entire datacenters. Their results would take too long to deliver if they do extremely complex queries.