How much do you spend monthly on hardware/bandwidth to run your MMO ?

Depends; World of Warcraft obviously spends more than Bang! Howdy.

David James (Three Rings, makers of Puzzle Pirates) had an interesting talk about making an indie MMOG here

One of the audiences asked that exact question ("what's your bandwidth/hosting expenses"), and the answer was <20K USD month. David also said the number disappeared compared to manpower expenses, and that he recommended moving to a co-located server once your game reached a certain size.

Allan

I would also really like to know how much bandwidth costs for game hosts. I know the game review side of the industry is extremely cost efficient when it comes to bandwidth. This is partially because bandwidth is getting pretty damn cheap now days. Right now my bandwidth is costing be about 2% of my earnings and I'm running at about 1% capacity.

I imagine bandwidth is a lot more expensive for actual hosts but you also have a lot of advantages. It is much easier to promote your own games through word of mouth. (as opposed to acting as a middle man) You also have more revenue options like finding sponsors or going with a gaming ad network like MochiAds.

If you know the bandwidth requirements of your client, and your target number of players then you can take a guess at your requirements, and thus take a guess at what hosting will cost you.

Client bandwith per second * seconds in a month * percentage of times players spend online * number of players = monthly bandwidth

e.g. Say the average client downloads 3kB/s, uploads 1kB/s, spends 1/9th of their time playing, and there are 1M clients.

3kB/s * 60*60*24*30.4 * 0.11 * 1,000,000 = 807 TB/month uploaded from server
1kB/s * 60*60*24*30.4 * 0.11 * 1,000,000 = 269 TB/month downloaded to server

Now combine those figures with the amount of data storage and processing power required, and ask a hosting provider for a quote ;)

These responses are great and all, but the question is directed to people who are currently running a MMO and how much it costs them monthly on hardware/bandwidth expenses.

no offense, but if you signed up on gamedev to ask that, then you're going about it all wrong. Pick up the phone and call some companies, or send some e-mails. Don't ask for exact figures, as I'm guessing they won't tell you.

Or order some yearly reports from any publicly traded publishing house/game company. It's all in there - exactly.

Not quoting from company internal figures *at all* (since that's illegal), but a fair expectation would be around 20k dollars per month on bandwidth for a moderately successful ( > 100,000 subscriber) MMO, and around 5k dollars per month for hardware.

That's based on knowing the prices a variety of MMO companies have paid over the last 7 years. YMMV (a lot) and what you should really do is contact companies that actually sell this stuff to MMO companies, e.g. the folks at OGSi (or whatever it's now called).