Funny you should mention this... I'm working with quite a few pissed-off developers who list their applications on Motrocity (which my mind keeps wanting to say
Atrocity), and I'm putting together a set of requirements to replace what these services provide, in full, but add a ton of additional features (which I won't go into here).
Basically do it right, without a profit motive, and give the developers 80%-90% of their revenue.
The other piece of this change from Motrocity that isn't made public, is that they've also clamped down on how developers can list their applications on their partner sites.
They're also asking developers to remove all mention of their own sites, their own support, and their other products. This gives the developers no way to track customers for upgrades.
They're also asking developers to provide a plain vanilla version of their application, minus any branding and customer service so that there's no way that the developers can have any further contact with, nor revenue from, the customer. This means that the customer has absolutely no idea who the developer is, or how to contact them, or how to find the developer's homepage to purchase other applications from them.
(Of course you could use the PGHQ search engine, but that is such a broken piece of garbage anyway, who would want to? It returns completely invalid, non-relevant results, and fails to return proper results for very specific keywords only found in specific application descriptions. Sounds very shady and "weighted" to their higher-paying partners to me).
Its out of control, and I'm spearheading the project to completely obviate Motrocity and their partners. Period.