In a simple test case (which is not necessarily realistic but a good illustration), if you request the same file 10 times from the same site (say within 10s) and have the db update interval set to 30s, sitestats does a number of db updates which could be consolidated.
Each request generates db selects followed by updates to SST_EVENTS, SST_SITEACTIVITY and SST_RESOURCES.
These could be optimized through consolidating identical events, e.g.
SST_EVENTS: consolidate events for the same user, site, event and date (i.e. one update that increments count by 10 rather than 10 updates that increment count by 1).
SST_SITEACTIVITY: consolidate events for the same site, event and date.
In real-life usage, SST_SITEACTIVITY is most likely to benefit from this.
It is also better for performance to put lots of writes (inserts or updates) into a single transaction than a set of separate transactions.