Semantic Indexing (or LSI) instantly sounds complicated, from a technical point of view it probably is, but when you break it down and understand WHY search engines are using this technique it makes much more sense.
The basic principal
The basic principal is to bring the best, most relevant results to the end user and is much like writing semantically, except that you write around a theme rather than a specific word or phrase.
Website Localization
Marketing your website is a main priority when making a business be successful online. The first thing that you need to consider and apply to your website is localization. By localization I mean generating traffic for your target location (where your business operates).
How many times have you done a search query and had a page of results that are not what you are looking for? Too many I guess. Well you ca do something about that, its not as difficult as you may think. Getting found for the term lets say ‘red widgets’ returns: 7.2 million pages, but adding the location increases the chance of getting found as the pages to compete against has been reduced to: 48 thousand pages.
I have long been a little hazy with regard to the nofollow attribute. Google has at last explained what they do when they see a nofollow and why was created. I have done several tests and some has been inconclusive but here below is Googles take it it. (keep in mind that other search engines may consider the nofollow rule differently).