Let me summarize the basic indicators of a website’s audience on three independent axes:

• The number of visitors
• The frequency of visits
• The time spent per visit

I have already mentioned the visitors, frequency. So, time spent is the last indicator to analyze (before attacking one on the web 2.0 analytics).

Why say so peremptorily that these three indicators may be enough to analyze the audience of a site?

You may think that I am monomaniac because I have already talked a lot of time : The GRP of the Internet (in French) or time for the user.

The recent decision by Nielsen to provide the total number of minutes spent on a site (in millions) proves one thing: the total time is the most correlated to the value of a site.

Based on a rough approximation, one can even say that the time is the equivalent of turnover. It's a rough approximation (the relationship between the turnover and the time depends on the economic model of each site, but for identical models, the analogy works), but let me use it a little ...

In the world of marketing studies of consumer markets, the products managers regularly receive the results of Nielsen (again!) or IRI panels. Any good product manager has only one thing in mind: maximize the sales of his brand.

And how does he split turnover?
He looks at the number of buyers, the frequency of purchases and the average basket value.

Why do we use this split?

Because these indicators are independent of each other.
You can increase the number of visitors, without affecting the frequency of purchases or the basket: by bombarding advertising targeted to attract new buyers.
You can increase the frequency of visits: by targeting advertising on those who are already customers to bring them back.
You can increase the basket: by conducting on-site promotions.

These three indicators also have the good idea to recreate the turnover when multiplied: turnover = Buyers x frequency x average basket.

On the Internet, the total number of minutes can be split in the same way: Total minutes = unique visitors x frequency of visits x time spent per visit.

When analyzed this way, web analytics becomes very simple. Just apply the same rules as in the consumer goods and play, when appropriate, on each of the three indicators. Reread the above example by replacing the words associated with purchases by those of the Internet, and you will see.

If it is so important, can time spent be measured as accurately as the value of the basket?

Yes, time can be measured with the required precision.

Both in “user-centric”, or in some "site-centric" tools such as ours, time is measured exactly.

Details of the measure will come later, but I will conclude by giving the definition that is used to calculate the time spent on textual contents (there are small differences for the video and audio contents): period during which the contents are visible by a user actively using the computer.

Don't you think that this definition is better than the ones usually used?