<xs:simpleType name="BillingModel" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:annotation>
    <xs:appinfo />
    <xs:documentation>&lt;summary&gt;Enumeration for revenue calculation methods used in AdBook.&lt;/summary&gt;</xs:documentation>
  </xs:annotation>
  <xs:restriction base="xs:string">
    <xs:enumeration value="NotSpecified">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;No billing model specified.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="UpFront">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;100% of the cost is paid during the first billing period.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="ProRata">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;Revenue calculations are pro-rated based on actual days that overlap a given drop.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="Special">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;Revenue is calculated externally and reported as 0.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="DeliveryUncapped">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;The total delivered quantity for the period is considered without regard to what was sold.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="DeliveryAccrual">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;Delivered quantity is capped at the pro-rated sold amount for each period.  Over/under delivery is accrued and applied to the following period for the
            life of the drop.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="DeliveryProRataLifeTimeCap">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;All periods before the last use ProRata.  The last period uses DeliveryLifetimeCap.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="DeliveryPeriodicCap">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;Delivered quantity is capped by the prorated sold quantity for each period.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="DeliveryLifetimeCap">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;The full delivered quantity for each period is used until the total delivered amount reaches the quantity sold on the drop.  After that the revenue is 0.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="ProRataEvenMonths">
      <xs:annotation>
        <xs:documentation>&lt;summary&gt;Same as ProRata except all intermediate months are considered to have 30 days.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="ImmediateOnContractDate">
      <xs:annotation>
        <xs:appinfo>
          <EnumerationValue xmlns="http://schemas.microsoft.com/2003/10/Serialization/">12</EnumerationValue>
        </xs:appinfo>
        <xs:documentation>&lt;summary&gt;100% of the cost is billable on the contracted date.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="BillableAtCampaignStartDate">
      <xs:annotation>
        <xs:appinfo>
          <EnumerationValue xmlns="http://schemas.microsoft.com/2003/10/Serialization/">13</EnumerationValue>
        </xs:appinfo>
        <xs:documentation>&lt;summary&gt;100% of the cost is billable on the campaign start date.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
    <xs:enumeration value="BillableAtCampaignEndDate">
      <xs:annotation>
        <xs:appinfo>
          <EnumerationValue xmlns="http://schemas.microsoft.com/2003/10/Serialization/">14</EnumerationValue>
        </xs:appinfo>
        <xs:documentation>&lt;summary&gt;100% of the cost is billable on the campaign end date.&lt;/summary&gt;</xs:documentation>
      </xs:annotation>
    </xs:enumeration>
  </xs:restriction>
</xs:simpleType>