Manually sets a user’s interest level on a particular tag temporarily, for the duration of the send.
horizon_set_interest( mixed tags , float score [, boolean only_increase ] )
Set the current user’s Horizon score for a particular tag or set of tags. This has no permanent impact on the user and only affects subsequent calls within the current message scope. This function is most useful to integrate a custom set of tags or user preferences with Horizon-collected data. For example, if the user has expressed the preference that he/she is interested in
music, and you want to define user preferences as being equivalent to a Horizon interest score of 5, you can set that directly using this function:
only_increaseparameter is set to true, then the interest score will only increase from its current value. So a user who already has a score of 10 will not be reduced to 5.