When generating an audience, you may encounter a situation where no users match the conditions you have specified. This is not to be confused with having an estimated audience size differ from the number of messages sent or your reported audience size is different from a previous point in time.
In this case, the number of users matching your condition is "0". After confirming that there is at least one user matching this criteria using the Profiles API or https://profileview.localytics.com/, the problem is usually due to sampling. Sampling helps us return estimates quickly within 1% error. So, this problem is especially noticeable when targeting a single user out of a large user base.
To find out if sampling is causing this issue, complete the following steps while on the Audience page with the Audience you are attempting to calculate:
- Using Google Chrome, right click the page and click "Inspect".
- Click the "Network" tab in the new window that has opened.
- Click the clear button (in the same window) that is a circle with a single line through it.
- Recalculate the Audience size and there will be an item call "adhoc" (still in the same window). Click that item.
- If sampling_rate is between 0 and 1 then it is most likely you are not seeing a correct Audience count due to sampling. If sampling_rate is 0 or 1 then the conditions you are attempting to target on are most likely not being set correctly.
See the image below with all of the items mentioned above highlighted. Keep in mind in this example there is no sampling.