In order to have an effective PPC campaign in Search Engine Marketing, you should employ negative keywords to avoid having your ads presented to people who are not searching for the purpose of buying your product or service. They may be looking for jobs, research information or other valuable information; but if they're not qualified or motivated to buy your products or services, giving them an opportunity to click on your ads is counterproductive in at least three ways:
1. It costs you the PPC fee, with little prospect of conversion.
2. It increases your 'bounce rate', and lowers your click through rate (CTR).
3. More bounces and fewer conversions lowers your Quality Score, increasing your PPC cost.
Negative keywords are your defense against these well-meaning searchers. Effective use of negative keywords will reduce your bounce rate (and website traffic commensurately) and ad spend, and increase your conversion rates.
Here are lists of negative keywords that can be used to avoid having your ads presented to job seekers, researchers, or people looking for free or highly discounted products.
Job Seeker Negative Keywords
Academic/Research Negative Keywords
book (unless you sell books)
books (unless you sell books)
case study (OK if you want them to read your case study)
case studies (ditto)
metrics (not always bad)
sample (may be OK if samples are part of your selling model)
training (OK if you sell training)
tutorial (OK if this is a tutorial for your product)
Free or Bargain Shopper Negative Keywords
second hand (OK if you sell used goods)
used (OK if you sell used goods)