Promise 100% and deliver 120%
No matter what you have to give 100% while dealing with a client. That is the only condition to be successful as a consultant.
To give my 100% I always ask for every detail of the business, the business model, avg. profit per conversion. And it is very necessary to keep in mind the best minimum conversion cost that a client can afford. In case of conversion cost being higher than the profit from one conversion, I also think upon the possibility of life time value of a client.
Similarly it is PERFECTLY legitimate that a client knows what images or language I am using to promote his/her business. So I always make a document and discuss every point with the client if it has time. Once everything is approved as ok, I go ahead and run the campaing.
Following up and reporting is as vital as performing according to the expectation to form a long time relationship. If I am transparent about my steps, the results and the hurdles, I know that I win his confidence.
While discussing a project and their outcome, it is PERFECTLY ok to be transparent about the limitations of a medium and you. I always believe in the theory of "PROMISE 100% AND DELIVER 120%".
Simplifying all these
1. Know your client, it's business and it's expectations.
2. Use all possible winning tools available.
3. Don't be dishonest to get a client.
4. Do discuss negative aspects and limitations.
5. Promise less, Deliver more, much more.
6. Always keep the exit door unlocked for the client and YOU.