Return on investment (ROI) is a measure of the successfulness of an SEO campaign. In the strictest sense, it is how much profit is returned from the investment. If money invested in a website promotion campaign produce sufficient profit to cover the campaign costs and still has a positive influence on Earnings Before Income and Taxes (EBIT), then the campaign should be launched. Likewise, if a campaign does not produce a profit, it should be abandoned in favor of other promotional vehicles.
But, it is often difficult to measure the specific profit from a website promotion campaign. That is because, not unlike most promotional efforts, it is difficult to isolate whether a visitor has made a purchase based on a single promotional strategy or the combination of may promotional strategies. For this reason the success of a website promotion campaign is typically evaluated based on the number of visitors it achieves. And since the number of visitors is intimately related to ranking results for high quality keywords, achieved ranking is a fair measure of the success of an SEO campaign.
Since there are many types of website promotional campaigns, your money should be prioritized where it will return the greatest value first. The following table will help define a sensible strategy of prioritizing your promotional budget.
| Website promotional campaign | Click-through1 | Market Share4 | Cost per visitor5 | Comment |
| Rank2 | % Visitors3 |
| LookSmart (primary search engine results for MSN) | A rank of 1-5 can produce in excess of 8% click through, sometimes as high as 15%
A middle page 1 ranking produces about 6% click through
A page 2 ranking produces less than 3% click through | 12 | Cost is based on 15 cents per click (visitor). | Although the number of visitors is lower due to weaker market share values, 15 cents is a good value. |
| Spider-based search engine | 88% | Cost varies depending upon: - Popularity of keywords
- Number of keywords
- Number of links to support campaign
Typical campaigns yield between 10-25 cents per visitor. | Well designed spider-based campaigns can produce the strongest visitor rate at very reasonable cost pre visitor rates. |
| Overture Sponsored listing | 1-3 only | 1-5%
most click through rates are less than 3% | 55% | Cost varies based on auction price per rank for each keyword. Minimum value is 5 cents per keyword. | Although Overture listings appear on lots of affiliate search engines, the click through rates are lower and the cost per keyword and maintenance effort can be very high. |
| AdWords (Google) | .05 to 3% | 45% | Cost varies based on keyword popularity and pre-determined price | Google’s AdWords produces reasonable volume at prices that can be lower than Overtures costs plus requires less maintenance. |
