With reference to this answer:
At the end of the day, we are delivering a product to a paying customer. This customer has needs and expectations, realistic or not. Often the sales team gets us into trouble just to get a commission.
I realise there are processes (mainly with communication and project managment) that can help minimise risk (these seem to have minimal impact, mainly due to being ignored by anyone other than dev) and believe a percentage of the problem is their complete lack of technical understanding rather than greed (though this does play a part). But when it isn't possible to get rid of commissions (very good article), get (train) better salesmen, or increase dev resources, how can you minimise the impact on developer moral, timelines and generally development department being held responsible?
How common is this damaging to the business (and no one higher up will believe how much better it could be - they don't see any problem now, but wonder why sales fall through and customers aren't happy) and how do others mitigate the risk, prove development is not the issue and handle such situations where the marketing is too aggressive and overselling is normal (which all propagates from the top)?
How can you support the sales team and upper management to improve the root cause of this situation and what changes can be implemented in dev department to help with this?
Additional information: the is only one product we create and as such is sold with additional functionality as required or work to let it integrate with existing systems.
I was worried about close votes, but this is a very real problem (and I have tried to word it objectively)- if you can comment on how to improve this question, please let me know.