All about linking
Links are the new craze with Webmasters, which is maybe why, if you haven't got a spam filter installed, you'll have received half a dozen invitations a week to join a link farm.
Bad links
... are from precisely the sort of spam email described above. The search engines are very sophisticated in detecting a sham, and if they sniff out a link from a web farm you are likely to be demoted, possibly even banned. Links from pages with low page ranking will help a little, but if there are hundreds of links on the page that won't do you much good. Some website pretend to link to you but switch off the link for search engines purposes, so there's all sorts of skullduggery you need to know about.
Good links
... are from well rated sites where the search engines can see a connection with your business. Catering and wedding hire is a yes, catering and xxx videos ... I don't think so. The link needs to be written with the search phrase you are trying top promote, ... but if you are still reading this then you are obviously interested in what we have to offer ... so contact us !
For best search engine results you need to develop links with sites that are complementary to yours. So in the case of Thierry's catering company who does a lot of weddings, he will be looking for links with wedding hire companies, limousines, basically anything to do with weddings.
high rankings with the search engines
The higher ranked your site, the more interesting YOU are to know. Any
webmaster worth his salt will leap at the chance of linking with a site
ranked 4 or higher, unless he is already in the super league of players
and doesn't need a leg up in the rankings.
The value of the link is proportionate to the amount of links from a page,
so its not very interesting getting a link from a page 4 ranked site if
there 100 links on it.