Backlinks are links from someone, to you. Links to you are a MAJOR way that search engines calculate how good your website content is. How good your website content looks is what a search engine calls relevance. Engines want to show the most relevant site to their users.
Industry links to you are the most relevant, and links from sites with higher rank. For example, Webeddy has thousands of links to us because of all the hundreds of websites we've built, a link from us has a lot of weight with the search engines. Just us putting a site in our portfolio can drive traffic quickly.
However - our thousands of links mean nothing compared to the millions of links from a site like msn.com, or digg.com. Getting large industry players to link to you, and getting all your partners to link to you can mean a huge improvement with the search engines.
Don't stop there - make sure the keywords they use in the link are relevant to the keywords on the page they are sending to, and mean something for your site. You can spend a lot of time going back and rebuilding these link relationships if you do it wrong the first time.
Have fun.
-- This article describes services that we can offer, link building is now part of our standard marketing packages when we engage a customer website project. --
Troy Anderson