A good SEO company will research your target marketing and competitors, and perform an SEO audit of your site and its content, combing through things like Google analytics and your other marketing channels.
This is essential for this type of full-service digital marketing agency to develop an SEO strategy to get you the best results possible. Their activities can include content marketing, copywriting, social media marketing, page optimization, and influencer marketing.
If all of these are done right, then your online presence should increase with measurable metrics including increased website traffic, sales inquiries, conversion rates, and engagement rates.