Management’s Discussion and Analysis of Financial Condition and Results of Operations - (continued)
(Amounts in Millions, Except Per Share Amounts)
assumptions or estimates have the potential to materially impact our Consolidated Financial Statements. Management has discussed with our Audit Committee the development, selection, application and disclosure of these critical accounting estimates. We regularly evaluate our judgments, assumptions and estimates based on historical experience and various other factors that we believe to be relevant under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.
Our revenues are primarily derived from the planning and execution of multi-channel advertising, marketing and communications programs around the world. Most of our client contracts are individually negotiated and, accordingly, the terms of client engagements and the bases on which we earn commissions and fees vary significantly. Our client contracts are complex arrangements that may include provisions for incentive compensation and vendor rebates and credits. Our largest clients are multinational entities, and, as such, we often provide services to these clients out of multiple offices and across many of our agencies. In arranging for such services, it is possible that we will enter into global, regional and local agreements. Agreements of this nature are reviewed by legal counsel to determine the governing terms to be followed by the offices and agencies involved. Critical judgments and estimates are involved in determining both the amount and timing of revenue recognition under these arrangements.
Revenue for our services is recognized when all of the following criteria are satisfied: (i) persuasive evidence of an arrangement exists; (ii) the price is fixed or determinable; (iii) collectability is reasonably assured; and (iv) services have been performed. Depending on the terms of a client contract, fees for services performed can be recognized in three principal ways: proportional performance (input or output), straight-line (or monthly basis) or completed contract.
Depending on the terms of the client contract, revenue is derived from diverse arrangements involving fees for services performed, commissions, performance incentive provisions and combinations of the three. Commissions are generally earned on the date of the broadcast or publication. Contractual arrangements with clients may also include performance incentive provisions designed to link a portion of our revenue to our performance relative to either qualitative or quantitative goals, or both. Performance incentives are recognized as revenue for quantitative targets when the target has been achieved and for qualitative targets when confirmation of the incentive is received from the client. The classification of client arrangements to determine the appropriate revenue recognition involves judgments. If the judgments change there can be a material impact on our Consolidated Financial Statements, and particularly on the allocation of revenues between periods.
The majority of our revenue is recorded as the net amount of our gross billings less pass-through expenses charged to a client. In most cases, the amount that is billed to clients significantly exceeds the amount of revenue that is earned and reflected in our Consolidated Financial Statements because of various pass-through expenses, such as production and media costs. We assess whether our agency or the third-party supplier is the primary obligor, and we evaluate the terms of our client agreements as part of this assessment. In addition, we give appropriate consideration to other key indicators such as latitude in establishing price, discretion in supplier selection and credit risk to the vendor. Because we operate broadly as an advertising agency, based on our primary lines of business and given the industry practice to generally record revenue on a net versus gross basis, we believe that there must be strong evidence in place to overcome the presumption of net revenue accounting. Accordingly, we generally record revenue net of pass-through charges as we believe the key indicators of the business suggest we generally act as an agent on behalf of our clients in our primary lines of business. In those businesses where the key indicators suggest we act as a principal (primarily sales promotion and event, sports and entertainment marketing), we record the gross amount billed to the client as revenue and the related incremental direct costs incurred as office and general expenses. In general, we also report revenue net of taxes assessed by governmental authorities that are directly imposed on our revenue-producing transactions.
As we provide services as part of our core operations, we generally incur incidental expenses, which, in practice, are commonly referred to as “out-of-pocket” expenses. These expenses often include expenses related to airfare, mileage, hotel stays, out-of-town meals and telecommunication charges. We record the reimbursements received for such incidental expenses as revenue with a corresponding offset to office and general expense.
The determination as to whether revenue in a particular line of business should be recognized net or gross involves complex judgments. If we make these judgments differently it could significantly affect our reported results. If it were determined that we must recognize a significant portion of revenues on a gross basis rather than a net basis it would positively impact revenues, have no impact on our operating income and have an adverse impact on operating margin.
We receive credits from our vendors and media outlets for transactions entered into on behalf of our clients that, based on the terms of our contracts and local law, are either remitted to our clients or retained by us. If amounts are to be passed through to clients, they are recorded as liabilities until settlement or, if retained by us, are recorded as revenue when earned.
In May 2014, the Financial Accounting Standards Board (the "FASB") issued amended guidance on revenue recognition which requires an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects