Every summer people ask whether they should be worried about declining traffic in a community.
Is this a blip or is it a dip? Summer or no summer, this is a simple thing to check.
1) Check if the number of people visiting your community has declined. If it has, this is an external factor. This means it’s not directly your fault. This might be seasonal variations (compare with last year), a hit to search traffic or referrals (check sources of traffic to see what’s declined), or a structural change to the site that makes it harder to find the community).
2) Check if participation ratios have declined. This is the number of posts per visit. If the same number of people are visiting but they are participating less, this is your fault (or responsibility). Compare the number of users to the number of posts to get a good idea. This usually means the quality (relevance/utility) of the community has declined. People are less interested in what’s in the community.
You could also dive deeper and check if the dip is because of top members posting less (sometimes a single highly active member disappearing can tip the scales) or if it’s more widespread among the entire group.
The same is true with spikes. If you see a spike in your metrics, diagnose it. Is it because more people are visiting or because those that visit are participating more?
Most dips are thankfully just blips. They’re seasonal (e.g. Christmas) and things soon recover. Seasonal blips are sharp and sudden. You should be more worried by slower, steadier, declines.