J-walk
i have the same problem.
it’s not such important how many users u have/per day. it’s more important how many users are at the same time. (or in my case ... overloading are cause by googlebots visits). when Gbot visit my site and open archive pages (btw ~18 000 articles are on my site), my server load increase to 80-104. so as result .. site overloading.
btw .. what’s ur db size?
and pls understand 2 different things.
bandwidth limit and CPU resources. u may have 200gb limit, but if ur site is hosted on 256mb ram PC, or there are a lot of sites on the same sharing hosting, u must use a lot of resourse.
what i did.
at first i move my site to VPS account (256mb RAM, 100gb bandwidht limit.)
still oveloaing
upgrade to 512mb ... every time gbot visit my site, site was overloaded.
after this i hire programmer, who create caching for my site.
once a day i upgrade my site (after this i delete cache) and site look likes as static site.
in my case (db size 70mb) i need something ~20-40mb space to store my cached files.
but as result i get ... 0 overloading and static pages. (fast loading)
that’s all ! 