Reseller Plans Comparison

Allocation based, Usage based, and Premium reseller plans all give you different ways of reselling web hosting services.

A table representation of this may explain this better.

Allocation Based Reseller Plans
Pro: Cost certainty - You know exactly how much your reseller plan is going to cost you every month. In order to be able to allocate out more resources, you would have to upgrade your plan ahead of time and you would know exactly how much this is going to cost you.
Con: Less flexibility - Your reseller limits are governed by how many resources you can allocate out. For example, if you have a 100GB disk space reseller plan, you cannot allocate out more than 100GB of disk space. Even if your accounts are using much, less than 100GB, if the cumulative total disk space you have allocated out is at 100GB, then you cannot create any more accounts.

Usage Based Reseller Plans
Pro: Plan flexibility - You can create packages as big as you want, they are not tied at all to your disk space limits. For example, if you have 50GB of disk space in your resller plan, you can create packages that are 100GB or 500GB in size. This gives you a lot of flexibility in what level of resources you can give your clients.
Con: Cost uncertainty - Since you are governed by the cumulative total disk space that your resold accounts have used, your limits are defined by how much disk space your resold accounts use in a cumulative total. For example, if you have 50GB of disk space in your reseller plan, then when the cumulative total of all of your resold accounts combine to use 50GB your accounts may be suspended to prevent them from growing larger. To prevent this from happening you would either need to upgrade to a larger plan or some how control how your clients are using disk space. Since you can never really know when your resold accounts will hit your reseller limit, you never know when you might have to upgrade and what your monthly costs would be.

Premium Reseller Plans
Pro: Plan flexibility - Just like Usage Based Reseller plans, you get the flexibility of creating packages of any size. You are governed by how much disk space is used.
Pro: Performance - Premium Reseller plans are placed on a high performance, SSD based servers. This gives you the ultimate performance boost and really sets your account and your resold accounts apart from other reseller services.
Con: Cost and Cost Uncertainty - Since you're governed by the disk space used, you can never be sure of when you might hit your reseller limits. Because the servers are high performance and SSD based, these servers just cost more, so the cost of the reseller packages are more expensive.