At myDreamDesigns we always impress upon our customers the importance of having a site correctly built for search engine performance, and the benefits of ongoing optimisation for the long term success of a site.
The major search engines (for the uninitiated the "Big 3" are Google, Bing (formerly MSN search) and Yahoo, with Google being by far the most prominent) and it can take several weeks or even months to list and rank a new site, but at myDreamDesigns we're perfected the art of submission to get new sites listed quickly, and will generally have the main pages of a new site listed within a few days, and returning successful searches not long after.
For existing sites built elsewhere and not performing to their full potential, we have a series of tried and tested remedial actions that can quickly turn around a non-performing site.
I always equate having a site that isn't properly optimised to spending a fortune getting an expensive company brochure designed and printed then not bothering to distribute it - a complete waste of time!
For any advice or help with search engine optimisation, myDreamDesigns are always a decent first port of call.