OK, here we go... one of my favourite subjects...
from the Alta Vista search tip [doc.altavista.com] page, or as they call it, their search cheat page, you basically have four different types of search here:-
1 - promotion website - finds either promotion or website
2 - website promotion - finds either website or promotion
3 - "website promotion" - finds the complete phrase website promotion, ie., those two words next to each other in that order.
4 - +website +promotion - finds pages that must contain website AND must contain promotion.
Numbers 1 and 2 would on the surface appear the same, but as Seth points out, there must be some syntax extraction going on that recognises number 2, 'website promotion', as a logical phrase and then gives it preference in the search.
One could question why 'promotion website' is not recognised as a logical phrase and that is because it isn't. 'Website promotion' is a phrasal verb, whereas 'promotion website' is simply an adjectival modified noun.
This used to stump me for a while until I started reading up on the search syntaxes available. You can really hone you search down with a little thought.
I rarely do a search these days without thinking first and then generally using a phrase that should be present on the types of pages I am looking for.
Lets say you are looking for a plant glossary.
* - Just typing those two words in would bring you a plethora of results probably not suited - 13,910
* - "plant glossary" would certainly narrow it down - 861
* - but "glossary of plant terms" would really give you a fine tuned result - 27!
* - Then again, "glossary of botanical plant names" would probably give you THE result, probably located in a university. Well, the result was Zero, but you get the idea.
Actually '+"plant name glossary" +botanical' gave the best result of 3 pages found, with number 2 being a university! (Ahhh, vindicated)
Try some experiments with searches and you will be amazed at how quickly you can get results without having to wade through the sloss.