number of ‘views’, ‘shares’, ‘comments’ and ‘likes’. This
makes sense as a starting point because of the key point
of difference online media have over traditional media –
it is social and interactive.
The use of social media for health promotion is
suggested to be most valuable for their potential to
engage with audiences.21 A common criticism of social
media is that, while they increase participation, they
actually lessen the level of commitment and engagement
needed to be part of a campaign or initiative.22 It takes
very little effort to like a campaign on Facebook, and
there may be no direct link between the number of likes
and the likelihood of behaviour change. Large numbers
of followers or participants may actually mean very little
in terms of how important or meaningful a campaign
truly is.23 Given that public health agencies are most
interested in affecting behaviour, it is essential to establish
if there is a connection between engagement and
behaviour change.
Engagement for the purposes of process evaluation
has been described on three levels:
1) Low engagement – an agreement or preference for
content, such as a like on Facebook
2) Medium engagement – people are involved in sharing
content with the capacity to influence others, such as
sharing or retweeting a campaign message on Twitter
3) High engagement – actual participation in offline
interventions that results from some exposure to
a social media campaign, such as making an
appointment for cancer screening.21
This engagement model could be adapted to measure
the level of engagement of participants in a social
media campaign that aims to change personal health
behaviours such as quitting smoking or eating healthy
foods. However, given that changing these behaviours
does not actually require participants to take part in a
real world ‘event’, engagement could be better stratified
in terms of those participants who had the lowest level of
online engagement (liking or following content but with no
further interaction) through to those who had the highest
level of engagement (interacting with all online campaign
activities and creating original content).
What remains to be understood or studied in depth
is how, or if, increased engagement and participation
increases the likelihood of action or behaviour change.
There is an underlying assumption, evident in the lessons
reported by the case studies, that fostering higherquality
online engagement leads to increased likelihood
of action. Evaluating whether this is true would be an
incredibly valuable contribution to the social marketing
literature.
Conventional process measures, such as the number
of likes, tell us little about a campaign’s impact on
behaviour. It is essential to move beyond the exhaustive
metric monitoring of process evaluations to outcome
evaluation. It is possible to extend and adapt process
evaluations to include more outcome-based measures.
For example, a key performance indicator for a social