Introduction
Back in July I wrote about keyword research for SEO. Although researching keywords for SEO is similar to that for PPC there still are many core differences.

In many cases using the generic targets with high searches can be very costly in the world of PPC. While they can offer a good return, often long tailed, very specific phrases can offer more qualified traffic at a lower price.

Categories
When it comes to any form of keyword research an Excel spreadsheet can be your best friend. I highly recommend using this to sort out your ideas before entering them into the PPC platform to prevent timely rearranging in the future.

Before you begin thinking of and gathering long lists of phrases, first decide where you want to drive traffic to in your site. This could be determined by anything from products or services, to specific informational landing pages and you may have a single destination or several.

Create columns in Excel that each will represent a specific category of phrases. Where you want to send traffic to will vary widely on the type of website you have. These categories will ultimately be used to define various Ad Groups in your PPC campaign.

If you are a real estate agent in Seattle, some appropriate categories may be; houses, condos, town homes & commercial. In this case you will want unique target phrases relevant to each category.

Geographic Targeting
Once you have your categories figured out you need to ask yourself what areas you will be targeting your ads to. Do you offer your services on an international level, or are you limited to a single country? Perhaps your services are limited to a specific city or state. These factors will contribute to your keyword choices.

Sticking with the real estate example, if you are selling real estate in Seattle, the generic phrase "real estate" would be a huge drain on your budget resources and would deliver a very low level of qualified traffic. In most cases targeting this phrase would simply make no sense. If, on the other hand, you are only displaying your ads to the geographic area of Seattle, the level of qualified traffic increases dramatically because only those searchers in the Seattle area will see your ad, and, if they are interested in real estate, your site and ad will be highly relevant.

For any campaign served up nationally where you are trying to gather traffic for a specific geographic region it is important to, in most cases, stay away from generic terms. Be sure that your ad copy also uses some form of qualifier such as a location, to help discourage clicks from searchers that are unqualified.

If you decide to go with a national or international campaign, you will most likely want to rule out the generic terms, and instead use more specific phrases such as "Seattle real estate" or "Seattle Washington real estate". This way, for someone searching from Miami for a property in Seattle they will view your ad as relevant.

Initial Phrases
Now that you have an idea of the categories and geographic targeting, it is time to start working on your keyword lists. Start by rattling off as many relevant phrases for each category that come to mind and list them in your Excel sheet.

Once you have exhausted all possibilities, go visit your site and the destination pages for each category. Are there any phrases that you have missed that will suit your needs well?

When it comes to PPC long tailed phrases can sometimes be very effective. While they may deliver a limited amount of traffic, this traffic is often very well qualified and more likely to result in a desired action. "Seattle 3 bedroom house for sale" may work well as a long tailed phrase, but remember, as your phrases become more specific, so should your landing pages. With this example, for optimal performance you would want to ensure that the visitor is directed to a page with listings for 3 bedroom homes.

If you find that your phrases under each category are closely related, but would require different landing pages, as in the above long tail example, you may want to add an additional column to the right, and beside each phrase paste in the most relevant URL for your site. You can later use this URL to ensure that each phrase drives traffic to the best possible location on your site.

Keyword Tools
Once you have gathered a solid list of keywords you will want to expand this to include as many relevant long tailed phrases as possible.

There are a number of keyword research tools out there with some of the most popular being Keyword Discovery, Word Tracker, and the still used Keyword Selector Tool over at Overture.

Using your favorite keyword tool enter the base phrase and scroll through the generated list gathering any other relevant phrases you may have missed. Unless your initial list is incredibly exhaustive, you will most likely find a number of additional phrases to add.

The main PPC platforms all have their own integrated keyword tools. These tools are really helpful to use after you have your campaign setup and your initial phrases posted into the appropriate Ad Groups. The Google AdWords keyword tool is great at finding a number of additional phrases. Once you have set up your campaign be sure to use this tool to check for any additional phrases you have missed.

Thinning and Adjusting
At this stage you should have an exhaustive list of relevant phrases. Now is the time to weed through this list. Remove any phrases that are simply too generic to be profitable. If you are a realtor, basic phrases such as, "house for sale", "real estate" etc., may be in need of removal (again, depending on your geographic targeting). Also be sure that no phrase is repeated twice. If you use the same phrase in two separate AdGroup’s this will cause a conflict and you will have little to no control for which AdGroup the phrase will be active.

Weeding out Poor Converters
Finding the initial phrases to use with your campaign is really the easy part. As your campaigns progress and you begin to gather click through rates and conversion data, you can then begin to weed out phrases that are either simply too expensive or are not converting. Assuming you have implemented conversion tracking codes, take a look at your cost per conversion for each phrase. If you find that a certain phrase is simply not giving you the return you are looking for consider pausing it, or reducing the maximum cost per click.

Summary
By creating relevant groups, determining your geographic targeting, and using the various keyword tools available, you should be able to gather a strong base of phrases for your PPC campaigns. General phrases such as "real estate" can become extremely costly and unproductive so do not forget to try various long tailed and specific phrases.

There are many other factors in having a productive PPC campaign including ad copy, landing pages, geographic targeting, conversion tracking etc, but without a solid base of keywords your campaign may be dead in the water before it even sets sail.