Remove all signs of Black-Hat from your site if you detect any.
Using Black-Hat techniques like keyword stuffing, hidden text, cloaking, duplicate or stolen content, link schemes, etc. may bring an immediate traffic boost that may last for a short period of time. However, sooner rather than later, these things will get you penalized or even completely banned from the search engines.
Here is a description of the most common of these techniques:
Keyword stuffing is the excessive use of keywords within the important areas of your pages. Remember that you create pages for users first of all, so make your content sound organic. Do not overuse keywords in TITLEs, anchor text and other important areas of your pages, as the SEs may consider this to be spam.
Excessive number of H1 headings was often used to manipulate the search engines results and get higher rankings for the certain keywords. Since then search engines have become more intelligent and they now want a page to have only one H1 heading. Pages with an excessive number of H1 headings are considered spammy and may get a website banned from search results overall.
Using duplicate or stolen content may lead to exclusion of your web pages from an SE index, so we strongly recommend that you avoid this practice. Your content should be fresh and unique, and bring value to the readers. If you are not sure about your copywriting skills, hire a good copywriter who will do this job for you.
A link scheme is a method of interlinking non-related sites in an attempt to artificially build backlinks and inflate PageRank to the pages that are being promoted. Search engines have already learned to detect most types of link schemes, so we do not recommend using this method of website promotion.