This is a common question in today’s competitive marketplace. There are so many unethical SEO firms and companies that don’t follow standard SEO protocols, it is becomes really had to separate the legitimate companies from the scammers and incompetent firms. Here are my recommendations.
The firm’s web site can be found in the top ten at Google for competitive search terms related to their services. If two or more companies are using these phrases to be at the top of the results at Google then this a competitive term.
The firm must provide references from current clients. Those clients should be able to tell you a number of things about the service provider. What is their response time to client inquires? How long have they been working with the firm? Has the SEO firm achieved any top three rankings for important keywords at Google yet? What are the firms strengths and weaknesses? How has their traffic grown since working with the firm? Can they determine that sales increased because of more leads from the Internet?
The list of items can go on and on but to me these are the most important factors in choosing the right search engine optimization firm.