If you are trying to locate an SEO agency, it's very difficult to come up with an appropriate list of criteria, especially in the event that you aren't familiar with the SEO procedure. Nearly every SEO customer will expect an SEO agency to rank at the top position on the most popular search engine results for all of their relevant keywords.
There are thousands of SEO businesses in existence and, with a small amount of spots in the search result it's difficult for all companies to prove their worth by appearing in the very first place. It's when you begin to dissect the top performing SEO companies that you begin to gain a greater understanding about why they're present and, most importantly, the reasons why you shouldn't use these companies. There are a myriad of ways to check an SEO firm, however I strongly suggest any person to perform the ones below, in addition to any other examinations you believe are appropriate.
Search for their company's name
The search engine for their company's name will undoubtedly lead to their listing in directories, articles submitted and social networking sites, however when the business is large, it will have some kind of feedback.
It's important to not consider these reviews as true as some unscrupulous SEO firms offer their services through this method If it's a forum, take a look at their posts count along with their joining date and responses from other forum members.