No limit on visitors per day. We also do not monitor bandwidth usage. What we DO monitor is CPU and RAM usage, and accounts that use too many resources will get suspended for high load. Normal websites shouldn't run into these limits (it's usually stuff like proxies that cause such suspensions). If you send a lot of emails you can get suspended as well (we limit email to about 50/day), but this is less common unless you have issues like forum spammers or malware.