Any good online marketing could tell you that in the long run, black hat SEO is a fool’s errand. While it may give your site and pages a token boost in rankings, it would eventually ruin them as well, and consequently, tarnish your reputation as a business. If Google Panda, Google Penguin, or any other similar ranking algorithm update were to catch you in the act, Google would impose severe penalties.
As you probably know, Google relies on an automatic algorithmic system to penalize websites it sees as “wrongdoers”. That said, the system is not infallible at catching bad SEO practices, which gives plenty of people the idea to somehow consistently break the rules without getting caught. This is also the reason why Google has no qualms about imposing manual penalties through its employees. If a person working at Google spots issues on your site, Google notifies you of the penalty though Search Console. A manual penalty can only be removed by making the needed changes and then asking Google to reconsider. On top of that, you would also have to explain how the issue was resolved.
Lower Rankings
One of the worst penalties Google can give you for black hat SEO is a drop in rankings. If you get in the search engine’s bad graces, you can wave goodbye to the number one spot, which at that point would be no more than a fantasy. Many penalized sites even fail to show up on the first few pages.
Blacklisting
Google does not come out and say they will blacklist you for conducting devious SEO, but they do delist websites that they see as spammy. Even sites that veer from the webmaster guidelines can get blocked. This is what you see when you encounter the red warning screen that shows when visiting some websites. If this happens to you, immediate redressal is called for, because if people cannot find your site easily, they will go somewhere else.
A good online marketing company would tell you the importance of freeing your website of viruses and spam messages and orienting its links and content to draw in human visitors, instead of just search engine spiders. While tricking a spider can work on a temporary basis, such shady tactics are bound to get you in the sort of trouble you do not want. Instead, focus on your visitors and making them happy, and you should do just fine.