Is your chariot being pulled fast and straight? The word chariot comes from Latin carrus; a war chariot was called a car. In ancient Rome and other ancient Mediterranean countries a biga was a two-horse chariot. I sometimes think of the biga chariot analogy when helping clients; the two horses being their sales and marketing teams. When cooperation erodes, it is almost always replaced by conflict. How can you restore cooperation, or better yet—ensure it from the beginning?

In order of importance, restoring cooperation may require addressing: 1) goals, 2) budgets (compensation and resources), and 3) responsibility. Let's work backwards from responsibility, as the 'finger-pointing' often seems to start there.

To more easily answer the question of who is responsible, I test by asking if you have the authority? Frequently I encounter people or groups being held responsible, but they do not have the authority. If you have the authority; you are responsible, and accountable. Sometimes responsibilities might be shared. When that occurs, identify and delimit the boundaries for specific responsibilities. Here are a few generic descriptions of responsibilities for sale and marketing. (To preface further discussion, I have taken the liberty of characterizing sales as tactical and marketing as strategic):
  Sales responsibility (Tactical - short-term: action(s) and how)
• Generate revenue selling widgets (pricing guidelines control profitability)
• Maintain existing customers, while developing new customers
• Provide customer feedback about current widgets and idea's for new widgets
• Manage forecast, pipeline, and appropriate KPI metrics
  Marketing responsibility (Strategic - long-term: plan(s) and what)
• Define new widgets and create pricing guidelines (marketing controls profitability)
• Create advertising to promote widgets and brand awareness
• Provide collateral materials: product brief, datasheets, corporate presentation, etc.
• Ongoing training about new products, competitive intelligence, qualified leads, etc.

Measuring performance. Implicit in the setting of goals, is the measurement of performance to those goals. Therein lies much consternation. Sales goals for the most part are quantitative, and quota's are immutable; as Yoda said, "Do or do not - there is no try". Measuring marketing goals have historically been more qualitative, and difficult to measure; Apple notwithstanding. "I know I waste half of my advertising dollars...I just wish I knew which half." Henry Procter of Procter & Gamble, circa 1895. Now, web-centric marketing activities have many tools available to measure performance. There are many ways to measure traditional marketing success too, even if the cycle is more long-term—it just needs to be implemented.

Budget. The budget should reflect the resources and compensation required by each functional group to meet the corporate goals:
  Resources. Each functional group needs to determine what resources are required, and allocate them appropriately.
  Compensation. Is usually the single largest component of any functional group budget (non-capital). Attracting and retaining employees is almost a universal corporate goal. In working with clients, a topic that is frequently raised from marketing is the compensation of the salespeople. I'll try to answer that question. In general, salespeople have an opportunity to out-earn their marketing counterparts. This is really an example of basic economic's; higher risk, justifies higher reward. Sales compensation plans include a variable, or discretionary amount, sometimes referred to as a 'pay-for-performance' bonus. The meaning is obvious, and many factors which salespeople can not control can affect that variable income. If marketing (or other functional groups) would like similar opportunities for financial reward, they should be willing to be held accountable for performance metrics, and be prepared to accept financial risk too.

Goal setting.This is the single most important element, and everything else hinges upon it. To build cooperation vs conflict, the senior management team must set mutually compatible goals, provide appropriate budgets (and resources), and encourage close cooperation and communication between the teams. The more each team understands the shared goals and responsibilities, the more closely they can work together to achieve those shared goals. Thereby being able to recognize and reward all of the outstanding performers.

Your mileage may vary...The opinions here are mine, based on almost three decades of experience, including as an executive with P&L experience having led both sales and marketing teams.