Search Engines are the main source of targeted web traffic, no doubt. That is why each and every business needs a search engine optimizer. As a result, the number of total search engine optimizers is increasing. In USA, the number of search engine optimizers is 363,857, and the worldwide number might be 1.7x larger (According to Moz).
Among the list of SEO professionals, a large number of them work as freelancers on various freelancing market places. They either act as consultants, link builders, or other specific parts of SEO.
Below are figures of the approximate number of SEO professionals in the top two online market places. (Based on their profile tags, the actual number could be less or higher)
Odesk = 117,988
Elance = 14,421
( Read the full story)