WHY GOOGLE MAY HAVE GIVEN YOUR WEBSITE A PENALTY
What people often forget, is that Google is a business. The search engine giants clients are its users and those users have an expectation of always being supplied with the highest possible quality search results.
This being the case, Google is constantly attempting to expunge poor web content from its searches; this and make sure that search results which it does provide are as safe, secure, and contextually relevant as possible.
The above being the case, a Google penalty usually happens for one of two reasons. Either Google has identified you as attempting to cheat its search algorithm in order to appear higher in search results, or your website has been identified as providing an unsafe and/or noticeably poor user experience.