This post covers some other ways you can continually brainstorm new keyword ideas.
Google Trends: Have you tried Google Trends yet? As an advertiser, you can use Google Trends to look at the search volume for different keyword ideas. Perhaps a new medical procedure was introduced to your field -- you can use Google Trends to figure out how users are searching for it. On the same page, you can also read the latest articles related to your industry so you can keep up to date on all the important, well, trends. Simply enter any search query or compare two or more queries and Google Trends will return a graph of search volume and related articles. Google Trends statistics are updated daily and you can look at specific periods dating back to 2004. You can read more about how Google Trends works.
Search Query Reports: The Search Query Report shows performance data for the search queries that triggered your ads that received clicks. Since this report includes search queries and their corresponding performance data, you can use this report to fine-tune existing keyword lists. Specifically, you can use this report to identify both new keywords and negative keywords that you'd like to add to your account to better control when you would like your ad to appear. You might also want to enter these terms in the Keyword Tool and see if users are searching for other similar terms. You can find a step-by-step guide on how to run a Search Query Performance report.
Forums and Wikipedia: Discussion forums related to your industry and online information sources like Wikipedia are other ways to learn how the general public perceives your product or service. Browsing different discussion forums is a great way to keep track of all the buzz related to your industry. If there are misconceptions about your industry, you can use this information to your advantage. Say you work in healthcare, and you realize that many are concerned about a new treatment option -- you can then try to address these concerns in your campaigns.
Google Search: Last but not least, use Google search to your advantage. Perform Google searches to see what the most relevant results are for both natural and sponsored search results. You can check out the sponsored results to see what other people are advertising and use natural search results to find sites you can browse for new ideas. Looking at these results can also help you brainstorm new negative keyword ideas so that you can better target your audience.Google, AdWords, Keyword, Tips and Tricks, Optimization, Series