I must disagree here. You can have one site that's very busy and utilises all of the bandwidth / diskspace allocated and another one that's hardly using a fraction of it. If somebody has 3 different domains they are managing, but all are really small - say few pages each, and hardly ever people visit it ? All they need is a small package with multi-domain support, and still they wouldn't be utilising their allocated bandwidth.
That's the point of having the bandwidth restriction and disk space allocation. Isn't it ? There's not necessarily a correlation between number of domains and performance / utilisation.
TCH should (and probably does) monitor the performance and try to 'spread out' the heavy accounts across different hosts in any case, whether these heavy ones are running one domain or not.
IMHO TCH should offer this as a an 'addon' service at a reasonable extra cost, or alternatively give discount to people buying more than one domain (but still not enough to justify a reseller package).
