Google does take into account the business theme of websites connected or backlinking to your domain.
If your site is about Web Design, you should concentrate on getting back links / link exchange from your niche sites i.e
Web Promotion
Web Development
Web Marketing
Internet Marketing
Web Design and Development
Software Development ( Web development can be termed as software development for large portal sites)
Ecommerce
Flash Design
Search engine promotion
etc etc.....
Getting links from your niche will help you gain higher rankings on search engines.
