we're looking for hosting recommendations for a relatively large phpbb forum. our mysql database is about 300MB and we generally run around 30-40GB per month, but sometimes more. i need a company that we can grown with. realistically, this forum will double in the next year. i would prefer a windows-based host with rock solid mysql servers, but will consider unix/linux.
Managing your own reseller account might be the right idea because of the excessive MySQL queries.
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A VPS or dedicated server is probably a better route for you to go. Most quality shared hosting that allows the bandwidth you are looking for is frequently going to cost you close to as much as a dedicated server and give you far less room to grow while staying in the same price range.
Then try getting some revenue... Selling advertising and/or placing Google Adsense ads on your pages and/or accpeting donations from your users might provide that additional monthly revenue depending on your type of audience.
I reckon Dinix should have the necessary experience with forums and their recommendation is not to be taken lightly. VPS would've been a temporay solution anyway, as you estimate that traffic will double within a year.
Just get a large shared account. Dedicated and vps mean you need to manage the server. Getting a vps is great if you want full control over the server, its not great if what you really want is just a large shared account. You'll be better off going with linux since mysql works better on it imo and overall its easier to find a unix host.