Here are the main advantages of mod_hosting:
1. Faster page loading - checkout the benchmarks we have performed.
2. No interruption of the customer's downloads (when someone is downloading a big file reload - this will cause problems. Restart will stop the download and start the apache again)
3. New domains/virtual hosts will start to work immediately on that server. No need to wait for web server reload/restart.
4. Each reload and restart generates quite a big load (especially if you want the best peformance). Initial apache start can take up to several minutes (if using NFS or if you have a lot of hosts).
Mod_hosting solution is perfect for servers with a lot of customers/domains - such as free hosts and hosting companies with powerful server(s) hardware, chasing for the highest number of hosted customers per server.