Search Engine Watch

Ask them which engines they have achieved the best results on. The ones that are important are the most popular engines, and these are the ones you want to see good results on. Since the popularity of search engines can change with the landscape of the overall Internet, check out the Nielsen Netratings page at Search Engine Watch.

You can access this at searchenginewatch.com/article.php/2156451.

Next, find out what keywords and phrases they are claiming great results with. It's easy to get high rankings with unpopular words. For instance, the keyword "cat leashes" will get high popularity ranking because no one else would think of using it. What you are looking for is good results using popular keywords. Check out the software Wordtracker, available at www.wordtracker.com.

You can order a free trial, or a subscription ranging from 1 day to 1 year. This software rates the popularity of keywords and phrases based on actual search engine use.

Next, look for good results over an entire site that the  company claims to have successfully worked for. You want to see a wide range of positions over a number of different search engines using different keywords or phrases for the entire site. Request a report for any client the company claims to have done well for. This report should show good positions on a number of the most popular search engines for a variety of different, popular keywords and phrases.