Although both Search Engine Optimization and Pay Per Click advertising use keywords to drive traffic, they are very different, and utilize keywords differently. If you are trying to expand your business’ online marketing efforts, then you should take the time to review the differences. 
What Are Your Goals?
If you are looking to start an SEO campaign, then you need to research the keyword landscape of the subject of the campaign. The keyword landscape is the list of keywords that most people use when searching for information on this topic. Each keyword relates either to the topic as a whole or to some aspect of it. Look at each, and try to figure out what use of that keyword says about the intent of the searcher. Once you understand the keyword landscape, select keywords that are specifically targeted to your campaign.
If you are trying to start a PPC campaign, then you need to research keywords that you can bid on. These campaigns need keywords that maximize the benefit to cost per click ratio. You should seek keywords that suggest a purchase, or something leading to a purchase, or that represent a subject matter that is profitable for your company.
At the beginning of your research, consider what the possible consequences of getting the keywords a little wrong would be. If even small mistakes could make a big difference in results, then take correspondingly more care with your research. After selecting your keywords, you must figure out where and how often to use them.
Keyword Use
For SEO campaigns, correlate the content on your business site with the keywords you selected. Each page on your website should have a single focus keyword or key phrase, with the content, title, and meta tags built around it.
For PPC campaigns, use the keywords that you selected in your ads, on your landing page, and in your ad groups. There should be a tight correlation between each of these, to maximize your Quality Score.
SEO and PPC Tolerances
SEO campaigns are very tolerant of mistakes with keywords. If one or more of your keywords are inappropriate, there will likely be little harmful effect, and you can easily try again. Accidental keywords might even improve your ranking in ways that you didn’t intend. Tailor the depth of your keywords to their location. Upper level pages should use broad keywords, and pages with specific details should use more specific keywords.
PPC campaigns are not very tolerant of mistakes with keywords. Each mistake costs money, so you need to analyze every selection minutely. Always stand ready to eliminate keywords that aren’t working, add new ones, add negatives, and keep checking the cost per click and the Quality Score. Tightly categorize your keywords by theme.
Summary
Remember, when designing your next online marketing strategy, that PPC categories are made by keyword rather than purpose, and competition metrics are irrelevant to an SEO keyword list. Although both types of campaigns use similar data, the data is not used in the same ways.
