As we’ve mentioned in an earlier post, keyword selection is one of the most important factors in creating a successful PPC campaign. In the world of pay-per-click advertising where you simply have to get the most of your advertising dollars, it pays to be choosy – and to be smart and savvy, instead of reckless, in making decisions about keywords.

Of course, this doesn’t mean choosing the most popular – and therefore most expensive – keywords. You have to take the time to research which ones are fit for your needs and budget, and which, when taken as a group, will still bring you high-volume traffic. Keyword research will require a set of tools that you can use to bring in the data, which can make you spend even more than you ought to. That’s why we’ve come up with this list of free keyword research tools that can potentially help you drive more traffic to your site and increase your conversions.

Wordtracker – Wordtracker has received lots of raves from Internet marketers and SEO experts alike. The great thing about this tool – which was created way back in 1997 – is that you can type in one keyword and get as many as a hundred variations for it. Wordtracker periodically compiles a database of over 330 million search terms, a compilation updated on a weekly basis. All search terms are collected from the major metacrawlers, like Dogpile and Metacrawler.

Google AdWords Keyword Tool – This tool comes in with a disclaimer saying it offers no guarantees to improving your pay-per-click performance, but Google AdWords Keyword Tool generates so many keyword ideas that it’s probably as valuable as any other free keyword research tool out there. Here you can enter multiple keywords and phrases and generate hundreds of variations, including misspellings and synonyms. Or you may want to generate keyword ideas by letting the tool study the content of your website: all you have to do is enter the URL. Once you’ve chosen your keywords among the results, you can export them as TEXT or CSV files and advertise instantly on Google.

SEO Book Keyword Tool – This is actually powered by Wordtracker’s API, and you can use it as long as you’re a registered member of SEO Book. (Registration is free.) SEO Book Keyword Tool can give you access to rough suggested daily search volumes by market for Google, Yahoo!, and MSN, as well as links to price estimate tools from Google AdWords. This free tool, moreover, links to various vertical databases like, Google Blogsearch, and to let you know if people are talking about your topic and what types of resources they are referencing.

Keyword Discovery – Keyword Discovery has a database of over 36 billion searches tracked over 12 months, making it one of the most comprehensive keyword research services available. Apart from helping you identify the top 100 variations and related keywords to that which you enter, Keyword Discovery also lets you find common misspellings, industry keywords, and the effects of seasonal search trends on the way you predict searches.

SpyFu – This free keyword research tool is particularly useful when you want to gain competitive intelligence. Why? More than just keyword variations, it gives you information like cost-per-click, cost-per-day, clicks-per-day, and the number of advertisers bidding on a particular keyword. SpyFu also lists out the top five competitors (including their domain and ad copy) advertising for the keyword you have selected. Indeed, it’s so much like spying, except that SpyFu is free and legal.

microsoft keyword trends
Microsoft adCenter Labs Keyword Forecast – This free tool forecasts the impression count and predicts demographic distributions of your keywords. You can enter multiple keywords and phrases at the same time – just separate them with semi-colons. Keyword Forecast uses time series forecasts to predict future impressions, while taking into account seasonality and historical trends. It’s helpful because having keyword variations is one thing; finding out traffic and demographic information is another. Use this to understand your target audience better, as well as how they behave and what they’re looking for.