The simple model is meant to get you thinking about the implications of cost versus revenue in terms of return on SEO.

For revenue I will be using the following formula, where monthly search volume is representative of [exact] searches from Google's keyword tool.

Conversion value will vary depending on the goal of your SEO campaign, for example; E-commerce sites could use average order value where lead generation sites might use their average lead value, in any case make sure you use an actual dollar amount.

The value of a keyword is pretty subjective based on your conversions, and therefore you need to utilize goal-specific conversion rates to customize this formula to fit your business.

For average SERP click-through I prefer to use an aggregate measure to project returns from larger scenarios, for example if I designed a model to target page 1 of Google I would use a 6.1% click-through rate, but if the model was specifically focused on top 5 rankings I would use 12.1%. These are just my starting point figures.

If you want to use more approximate measures of average click-through for exact rankings, a very helpful case study from Slingshot SEO on SERP CTR produced this lovely graph:

Slingshot dives into the details of their study here on Moz, and very recently Geoff Kenyon posted his thoughts on SERP click through rates , so you have some starter data.

18% lines up much closer to my historical SERP performance data than the previously reported data from Optify, which posited a potential of a 36.5% CTR for position #1 .

Using just the four metrics from the simplified model, I have created a worksheet that you can use.

Within the spreadsheet you will see there are 2 sheets; Simple and Advanced, and all values that drive the model are highlighted in yellow.

Use the simple model to get a basic sense of how things work; how different values for different metrics will impact your total monthly revenue, and don't be afraid to make adjustments and get creative.

Try inputting the lifetime value of a customer to forecast far into the future or bake in a measure for time on site and how certain thresholds may lead to higher variable conversion rates. If your goal is to drive newsletter signups, measure it; think outside the box! Then let me know in the discussion area to the right what you did!

For cost assumptions I'm going to use average costs associated with developing one URL targeting one primary keyword. In this scenario I'm assuming the website already has a baseline of steady traffic, but not much, say 5,000 visits per month or so. This is important to note because it reduces the need for additional link building or paid advertising promotion for posts to gain enough rank signals to make it to page one.

For this model, the costs associated with content development are:

Research
This represents the average cost to do post-level keyword research and compile a matrix for the URL.

Writing
This represents the actual ideation and writing of all of the content for the URL.

Production
This is representative of the editing and actual production of the content; final proofreading, formatting images, and loading into the content management system for publication.