Odds are that if you see your site either losing rank or just not moving past page 3 or 4, the issue might be shallow or poor content.
Google recently announced Rank Brain which is an artificial intelligence component of their search algorithm. What this means is that they are also moving in another direction in how they determine how a site matches the query entered into their search engine. SEO for small businesses in Atlanta is becoming a much more complex component of their marketing mix and can overwhelm even the most savvy marketers.
Recent Penguin and Panda updates are thought to be one long roll out which means they don't actually have an end. What this means for your website is that your SEO needs to be an ongoing process that keeps up with the ever changing world of SEO.
Control What You Can
You can't control what Google does so the only control you actually have is over your website. Constantly evaluating your content and it's performance can help you to improve the rank of individual pages and also potentially increase your conversion rates. Auditing the content of your site on a regular basis to ensure it's actually providing the answers to the questions an end user typed into the search engine to begin with is going to pay dividends in the long run.