A few ways you can do this.
- You can add a choice in the flow step, you have two choices: if score is greater than or equal to 0, change score, else do nothing.
- You can set a nightly or weekly scheduled batch campaign to run on people whose scores are below 0 and change those scores back to zero.
- You can set a triggered campaign fixing the score back to zero. Triggered when score changes and new value is less than 0, change the score back to zero.
Depending on how many decay campaigns you have (smart campaigns that subtract points from a score) , I'd probably choose between options one and two. If you only have a few, the first option is easy to implement. If you have hundreds of smart campaigns decreasing scores, the nightly or weekly scheduled batch campaign is going to be a quick solution to your problem, and doing nightly or weekly batches is a better use of processing power than triggered campaigns running to fix things (#3).
Cheers,
Edward Unthank | Founder, Etumos