There is no mean average for time spent on a campaign style site. Just as
with every other form of outreach, your audience will have different
thresholds for what they want to do based on the actual features you offer
and their personal interest in the campaign. The key things to measure are
not really time spent on a site overall, but actions performed working with
specific features, recidivism, and conversion rates (or achievement of goals
for all the people working with Google Metrics).

Some of the features that generally increase the time a user will spend on a
site are social networking components, blogs, forums, etc. where they can
share their thoughts as part of a community of users and build affinities of
interests with other members. The average time a user will spend
participating is influenced by a number of factors, chief among them the
level of participation by other members of the community. If there are
robust conversations and real opportunities to grow relationships, users
tend to spend more time examining what is going on and finding ways to
participate.

Recidivism speaks to the tendency of users to return to a site, independent
of any specific features, and generally web metrics tools are the best way
to track these numbers. One of the factors that chiefly influences this
metric is the use of push technology such as mailing lists, SMS components
and other forms of notification (such as alerts when new content has been
posted). It is often useful to track people who return as anonymous users
separately from those who enter the site as registered users, as the
behaviors of these groups almost universally differ.

Conversion rates speak to the tendency of users to perform specific actions.
In the context of a campaign style site, this can include participating in
an online petition, making a donation, sending a letter to an editor,
calling their representative, and other forms of action akin to those of
traditional online communities like creating user accounts, posting to a
forum, etc. Conversion rates are a key metric in that they track how
effective the online tools are that you are actually putting out there.

Creating a metric system to judge the effectiveness of all of these
components is a matter of tying numbers in each of these areas to specific
goals (i.e. do you want someone to do something, participate in something,
build relationships, etc). Time spent using specific features can be a valid
metric, but it alone is rarely a strong indicator of the effectiveness of
any particular form of outreach.

At my company, we often track specific outcomes in relation to features
using web based metric tools and other methods of analysis specific to the
tools we work with. In general, we find that 4 – 8% participation rates in
any specific category are general indicators of success at the initial
launch of a project, and look to outliers as indicators of the usefulness of
particular features. If no one is using the forums on a particular site but
10% of users are checking out the social networking features, that is
generally a good indicator that putting more emphasis on personalizing a
site will lead to better outcomes. Similarly, if 50% of users are reading
position papers but only 3% are looking into the blogs, it may mean blog
features need to be promoted in new ways to make them effective.

Something to remember is, over time, the majority of traffic to most
publicly available sites will be anonymous web users who will visit the site
once and never come back. This figure is regardless of the actual features /
options / goals that are offered, and it heavily influences the average
amount of time spent on a site. Means and modes in terms of time spent are
usually more interesting to understand; even if 90% of people are there for
under 30 seconds, the other 10% becomes the important group to target.

Michael Haggerty