Without keyword research, you can’t possibly know which terms you should be optimizing your site for. You need to identify a wide range of terms pertinent to the subject of the site, identify which ones actually have the potential to drive traffic, and further identify which terms are going to be easiest to rank for. SEO Keyword Research software helps accelerate this task. Good keyword research programs will help generate lists of keywords, including synonyms and related terms you may not have thought of. They will let you know how many searches are being performed for these terms on the top engines, and will let you know how many sites potentially can turn up for those terms. Most will let you know the bidding level for those terms in paid search ads, which further helps you gauge how intense the competition is for those terms. These tools are also highly useful for PPC campaigns. They help you identify terms to bid on, and also help you assess the potential costs.