1) If you used multiple communication channels, it is likely that there will be some overlap in the reach achieved by each channel, which will result in double counting the people you reached. Unless your campaign can quantify how big the overlap was (e.g. by surveying the target audience members), the best thing you can do is to 1) acknowledge that there might be an overlap; and 2) report on the reach achieved by the individual channels, in addition to reporting the total reach.
2) To gain more meaningful data, consider differentiating between:
- passive reach, such as the number of people who saw the campaign’s social media post or read an article
- active reach, such as the number of people who attended meetings, were engaged in an online discussion, etc.
3) Report on the responses you received from people who were reached by the campaign.