The company must also be using ethical approach in promoting or optimizing your site known as white hat SEO. You will easily determine that – if they offer to rank your website in just a short time. If you are aware of how SEO strategy is done, then you know that putting your web on the top rank takes little time. If a company says – “100% guarantee” or “Increase your SERP with a Week/Month” or “100% Guarantee High SERP” or anything that is too good to be true, you have to understand that that company will be using unethical SEO techniques known as black hat SEO. And black hat techniques will always hurt your website’s rank and reputation. Even Google will penalize your website just for using unethical or black hat SEO service. And eventually you will lose your visitors and business.