Google is a Mathematical Equation, Not a Mythical God
Google creates a level playing field where the Davids and Goliaths duke it out for ranking. Google does not reward or punish but assesses according to a mathematical algorithm impartial to whether you are General Motors or Tesla. This algorithm is constantly challenged and changed as hackers rise to the opportunities to buy, cheat or piggyback their way to the top ranking.
Like a game of snakes and ladders, a company can step up in the rankings only to slide into oblivion because some enterprising but nefarious rogue chose a promising site to invisibly latch onto with a portal to a porn site. Some have seen their traffic increase meteorically only to witness it abruptly disappear off the radar when the Google 'bot' catches up and cuts the site like a ripe banana.
What can you do if that happens? Nothing. Just start over. But make sure your site is protected and healthy. Watch your statistics with Google Analytics. A spike in traffic should follow a significant event or posting. This way you stay clear on what is working for you and what might be suspect. Build your traffic in a credible way. There are lots of offers to buy mega numbers of followers or lists. Beware. There are no short cuts. They will inevitably get you lost. If not in rankings, in your reputation and customer perception which is infinitely harder to recover.
The next question is how, then, does Google know if are a Neurosurgeon - just because you say so? Your credibility is what the algorithm assesses. How it does that is by watching your website for traffic – how many people key in your URL? For references – how many other sites, preferably larger sites like educational facilities, ezines and such, link to you? How often do you add relevant content to your site? When there is little new activity on a site the Google bot does a larger orbit before returning to check your site for news. Where is your traffic coming from? Blogging or adding pages of interest (see Meta Tags, Keywords and the Informed Consumer) will increase your credibility and traffic. Social Media connections are invaluable and a separate topic.
Welcome to the Global Google Mall
Whether you are B2B (business to business) or B2C (business to consumer) you need to be in this mall. Some years ago there were competing search engines, but Google pulled out in front for one reason and one reason alone and that was it delivered what the customer wanted with speed and accuracy that outperformed its competitors.