I have had clients that used a SERP (basically a “ranker”) when approached by another company, and they showed our client that they weren't a top result when searched – and by the way there about a million sites that yield different SERP numbers. Yet our clients traffic has increased over 300% year over year. They were told, “you need more links”, we can do link building like no other. Our client was told, you are paying too much, we can get you the #1 spot thanks to our unique approach. Now correct me if I am wrong, it isn't about our approach, it is all about Google's approach and catering to it.
The client is still with us, but you hear these stories on a daily basis. Obviously you know that SEO matters to your marketing efforts, but how do you know who to go with? Ask for research and results from previous clients – this will give you a huge understanding of their abilities. Our focused research is what sets our bar so high and why we consistently experience triple digit growth in traffic for our clients. At the end of the day I encourage to spend $20 – buy a book on understanding SEO, so you have some basic knowledge…then start asking questions and see if you feel good about the responses you are getting. If you don't feel good about the responses…call us. It works on mobile too…