and healthcare advertising. Our client contracts are primarily fees for service on a rate per hour or per project basis. Revenue is recorded net of sales, use and value added taxes. 

Performance Obligations - In substantially all our disciplines, the performance obligation is to provide advisory and consulting services at an agreed-upon level of effort to accomplish the specified engagement. Our client contracts are comprised of diverse arrangements involving fees based on any one or a combination of the following: an agreed fee or rate per hour for the level of effort expended by our employees; commissions based on the client’s spending for media purchased from third parties; qualitative or quantitative incentive provisions specified in the contract; and reimbursement for third-party costs that we are required to include in revenue when we control the vendor services related to these costs and we act as principal. The transaction price of a contract is allocated to each distinct performance obligation based on its relative stand-alone selling price and is recognized as revenue when, or as, the customer receives the benefit of the performance obligation. Clients typically receive and consume the benefit of our services as they are performed. Substantially all our client contracts provide that we are compensated for services performed to date and allow for cancellation by either party on short notice, typically 90 days, without penalty. 

Generally, our short-term contracts, which normally take 30 to 90 days to complete, are performed by a single agency and consist of a single performance obligation. As a result, we do not consider the underlying services as separate or distinct performance obligations because our services are highly interrelated, occur in close proximity, and the integration of the various components of a marketing message is essential to overall service. In certain of our long-term client contracts, which have a term of up to one year, the performance obligation is a stand-ready obligation, because we provide a constant level of similar services over the term of the contract. In other long-term contracts, when our services are not a stand-ready obligation, we consider our services distinct performance obligations and allocate the transaction price to each separate performance obligation based on its stand-alone selling price, including contracts for strategic media planning and buying services, which are considered to be multiple performance obligations, and we allocate the transaction price to each distinct service based on the staffing plan and the stand-alone selling price. In substantially all of our creative services contracts we have distinct performance obligations for our services, including certain creative services contracts where we act as an agent and arrange, at the client’s direction, for third parties to perform studio production efforts. 

Revenue Recognition Methods - A substantial portion of our revenue is recognized over time, as the services are performed, because the client receives and consumes the benefit of our performance throughout the contract period, or we create an asset with no alternative use and are contractually entitled to payment for our performance to date in the event the client terminates the contract for convenience. For these over time client contracts, other than when we have a stand-ready obligation to perform services, revenue is recognized over time using input measures that correspond to the level of staff effort expended to satisfy the performance obligation on a rate per hour or equivalent basis. For client contracts when we have a stand-ready obligation to perform services on an ongoing basis over the life of the contract, typically for periods up to one year, where the scope of these arrangements is broad and there are no significant gaps in performing the services, we recognize revenue using a time-based measure resulting in a straight-line revenue recognition. From time to time, there may be changes in the client service requirements during the term of a contract and the changes could be significant. These changes are typically negotiated as new contracts covering the additional requirements and the associated costs, as well as additional fees for the incremental work to be performed. 

To a lesser extent, for certain other contracts where our performance obligations are satisfied in phases, we recognize revenue over time using certain output measures based on the measurement of the value transferred to the customer, including milestones achieved. Where the transaction price or a portion of the transaction price is derived from commissions based on a percentage of purchased media from third parties, the performance obligation is not satisfied until the media is run and we have an enforceable contract providing a right to payment. Accordingly, revenue for commissions is recognized at a point in time, typically when the media is run, including when it is not subject to cancellation by the client or media vendor. 

Principal vs. Agent - In substantially all our businesses, we incur third-party costs on behalf of clients, including direct costs and incidental, or out- of-pocket costs. Third-party direct costs incurred in connection with the creation and delivery of advertising or marketing communication services include, among others: purchased media, studio production services, specialized talent, including artists and other freelance labor, event marketing supplies, materials and services, promotional items, market research and third-party data and other related expenditures. Out-of-pocket costs include, among others: transportation, hotel, meals and telecommunication charges incurred by us in the course of providing our services. Billings related to out-of-pocket costs are included in revenue since we control the goods or services prior to delivery to the client. 

However, the inclusion of billings related to third-party direct costs in revenue depends on whether we act as a principal or as an agent in the client arrangement. In most of our businesses, including advertising, which also includes studio production efforts and media planning and buying services, public relations, healthcare advertising and most of our CRM Consumer Experience businesses, we act as an agent and arrange, at the client's direction, for third parties to perform certain services. In these cases, we do not control the goods or services prior to the transfer to the client. As a result, revenue is recorded net of these costs, equal to the amount retained for our fee or commission. 

