In fact, identifying a good SEO company isn't as hard whenever think it is.
Beware of SEO firms that promise fast results though. The waiting time for indexation is unpredictable, but expect you'll allow 3-4 months. https://WWW.Youtube.com/playlist?list=PLbZg6jL4FgfAS0TjMKfQ3hKiYOikfzmuE