The concept of interlinking different website together, and also centralizing links to a single website, has been in existance for awhile. In the orginal stages, the concept existed in the form of building link farms or mini-site networks for the sole purpose of increase backlinks across various domains. Now link wheels have transformed to use high PageRank (PR) web 2.0 properties that search engines view with high authority. So while the orgin of the "spokes" has changed over time, the effectiveness of link wheels still hold true today and our team utilizes link wheels to gain high rankings on even some extremely competitve keyphrases.
Link wheel building is one of the recent popular techniques for creating one way inbound links for any websites from various web2.0 websites. Now link wheel building is one of search engine marketing strategies for promoting a website to the higher position in organic search engine result pages for specific keywords. Incoming links is one of the major factors in search engines SEO ranking systems. Quality incoming links from niche topics will help the website for better ranking. Many search engine marketers are using link wheel methods for quickly boosting website rank on search engines. But if the strategy is not used perfectly then it will bring no or very less value for your website.
Link wheel is something which comes out of your SEO work naturally, I've never even tried to count those wheels. However, building link wheels is very important, it helps your overall SEO activity not to look spammy by formally promoting other websites or web pages where your link rests.