How do I know you are good at SEO?

Had a meeting with a prospective Client earlier and he asked me this question, “How do I know you are any good at SEO?”
This is a perfectly valid question but I was taken aback because no one had ever asked it before.  I know that sounds strange but most of our clients find me online or are referred to me, in which case, they already know I’m “good” through that referral or search.  But this client was a walk-in.  He found our office because his friend was working in the same building.
Anyway I’m pretty sure you can tell if an SEO is “good” using the following metrics:

1.  Look at their Client List –  There are two criterias that need to be met here 1) That their client lists are ranking well for their keywords and 2) That they are affiliated with locally trusted businesses.
   Some Prime Examples:If you search for our client, Captain Marvins (www.captainmarvins.com) – they are currently no. 1 on Google for “stingray city tours” – Captain Marvins is also one of the oldest and most trusted businesses in the Cayman Islands.If you search for our client, Living the Dream Divers (www.livingthedreamdivers.com) – they are currently no. 2 on Google for “cayman diving” – LTD Divers has also been voted the Top Adventure dive company in the World by TripAdvisor.
2. Look at their Website Rank – If they are on the top three of their industry keywords and keyword permutations then they pretty much know what they are doing.  Easywebsites.ky is currently no. 1 for “cayman web design”; “cayman islands web design”; “cayman web development” and most other permutations.  Go ahead and search for us on Google.  You will also notice that we are no. 2 for, “cayman seo” second only to our blog.
3. Read their Blog and see if you are learning a few things while reading – every qualified SEO Professional will have a blog that is continuously updated almost meticulously.

You will notice that I actually have 2 blogs, one for my Small Business SEO and one specifically for Cayman SEO.
It is vital for your business to choose the right partners so this was a great question, thanks for asking!