"I just wanted to let you know that Ben has been so great with us. I know we were picky (to say the least) before/after our new site went live, but Ben was responsive the whole time. He continues to help us out with website stuff and we really appreciate everything he has done! Also, Chris has been wonderful with SEO stuff as well. He has been very helpful with the SEO project and helping me not let things fall through the cracks. You have a great team and we have enjoyed working with them!"
Additionally, there are many situations where PPC (a component of SEM) makes more sense than SEO. For example, if you are first launching a site and you want immediate visibility, it is a good idea to create a PPC campaign because it takes less time than SEO, but it would be unwise to strictly work with PPC and not even touch search engine optimization.