For a broad overview of the RFM Segmentation concept, please view this article, first.
Note: When this Frequency campaign is successfully published, it is correct that it will usually show 0 Active Contacts in it. Contacts will go into this campaign when they purchase and then - after a short delay while being an Active Contact - they will get their rating value set and be finished with the campaign. Both the Frequency and Monetary campaigns will regularly have 0 Active Contacts in it. Only the Recency campaign has Active Contacts in the campaign, as a result of the campaign's Delay Timer countdown to set the Recency scores.
How to Set up and Publish Your Order Frequency Campaign
How to put your Past Customers through the Order Frequency Campaign
Although this process in the video below will be necessary after you launch this campaign for the first time, it will also be necessary if you ever need to change your score ranges in this campaign and re-publish the campaign. Running this process below will update the scores for your customer base to the new score ranges; otherwise, your scores would remain according to your old settings.