For instance, a good deal in business is one where you all a good for more than it costs.
If you were a freelance developer, that might mean charging a large amount for a feature of high business value because you know the client will pay, even though it doesn't cost you much to do.
Another aspect is information asymmetry. In the above instance, lieing about how many hours the feature would range to implement would be unethical for sure. But not saying how long it would take - charging for features and keeping the cost to implement to yourself - probably not.
Then we get to practices like subscriptions you expect people will forget to cancel (see every consumer facing sas), or building a platform with the intention it will be hard to leave (no export or api = a moat = Facebook)
Are these unethical though? I think mostly not. You need a business model, and business models mean not running things like you are doing a favour for your uncle. I think the line is where you mislead or get your customer to do things potentialy against thier interests without telling them they are taking a risk.
To have a career and your basic needs plus some met? no
To be an industry leader\ceo of wealthy company? evidence suggests it wouldn't hurt to be a bit "flexible" (http://www.cnbc.com/2017/03/21/apparently-psychopaths-make-g...)
Find some meaning\goal and work to it. Trying to put a number or fixed value on something so nebulous is a waste of time.
How you deal with this reality is up to you.
I would argue that you don't every need to cheat your own self to be successful.
What about Nazis or USSR's NKWD - I hardly doubt that all of them knew that what they're doing is immoral.
I think if you tell a different sort of story about what you're doing, that it's something worthwhile, and that success involves being a person that people can rely on... well, I don't think being unethical will help you much.
I suppose if you have enough power, people won't give a damn about your ethics. But I think if you can get to the middle without hurting a lot of people, you're going to be identified as one of the people the rest of the middle would like to have at the top.