bob
It's better to have two hands than one glove.
Well it is a part of our job. I can respect it not being a part of your's. I guess the difference between us is that I understand that if a client is conscious of their customers' tastes and promotes their business accordingly, they have a better chance of being successful. I have also found that a client that is more successful is more likely to return and hire us to do more work. Our best clients have and most likely always will be the repeat customers. But that's our business. I recognize that not all businesses are run the same way. I'm sure there are plenty out there that have done quite will with the "one and done" mentality. It just doesn't fit for us.
If your client's success or failure is important to you then you should do whatever you can to ensure that success.
I've always considered worrying about my impact on someone else's success to be riding thin odds. 'Thin odds' being a politic way to say 'micro effect'. If someone's is or is going to be successful, they will be so with or without me. If another's business is going to suck the pipe, it will also do so with or without my efforts.
If, on the other hand, there is a business so delicately balanced on the edge of success or failure that I can push it one way or the other, the probability of this being the case is so minute that one might be considered a fool for being overly concerned with it.