Reputable SEO companies do not spam blogs. That's spam. Any comment you received blathering on about SEO is spam. Mark it as spam - don't delete it. That way Akismet will learn to sequester it.
The vast and overwhelming majority of all so-called information on the internet is spam. Over 80% of all comments submitted to .wordpress.com blogs every day are spam. If you get spam that slips by Akismet then mark it as spam ( do not delete it) and over time Akismet will learn it's spam.
It takes only seconds to click "empty spam" and you don't even have to click "empty spam" if you don't want to. Akismet will maintain comments it has caught for 15 days from the time they were received, and then it will delete the comment automatically.
Please take the time to read "5 things every blogger should know about spam" on this page Akismet: How it works