The Right Keywords: If someone searches for your products or services, what phrases would they use? Write
them down and see what the response is. Interestingly enough, some of the phrases may not be what your customers use.

At the same time, ask your current customers how they search.

Unfortunately, it's not uncommon for business owners to waste most of their budget on ineffective search terms.

Be specific: If your search phrase is too generic -- such as buying "auto dealer" -- the costs will be prohibitive and you'll likely get non-relevant traffic. Instead, try to narrow the phrase. For example, you might buy "Ford auto dealer Los Angeles."

Ad Copy: You only have three lines to convey your message. While this seems like a minimal amount, it should be enough.

Now, just like search phrases, you need to be specific. In fact, it's a good idea to use the same words you use in the search phrases.

Conversion: Once a visitor has clicked your ad, you need to find ways to convert them into a customer. Perhaps one of the best approaches is to setup a landing page. Essentially, this is a new web page that has similar copy to your ad and a form to capture the lead. For the most part, make it easy for people to get started, such as providing a free trial.

Outsourcing: If you don't have the time to do your own campaign, there are third-party providers that can help out. One example is Web.com, which has a variety of affordable online marketing packages.

Also, there are some good books on the topic, such as Ultimate Guide to Google AdWords: How to Access 100 Million People in 10 Minutes and Landing Page Optimization: The Definitive Guide to Testing and Tuning for Conversions.

Tom Taulli is the author of various books, including The Complete M&A Handbook, You can reach him at his personal blog.