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  <xs:element id="sst_ScheduleOfAccruedExpensesAndOtherLiabilitiesTableTextBlock" abstract="false" name="ScheduleOfAccruedExpensesAndOtherLiabilitiesTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="sst_ScheduleOfShareBasedPaymentAwardOtherThanOptionsValuationAssumptionsTableTextBlock" abstract="false" name="ScheduleOfShareBasedPaymentAwardOtherThanOptionsValuationAssumptionsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="sst_S1HoldcoLLCMember" abstract="true" name="S1HoldcoLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_S1MediaLLCMember" abstract="true" name="S1MediaLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TermLoanMember" abstract="true" name="TermLoanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_NetWorkingCapital" abstract="false" name="NetWorkingCapital" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_GoogleMember" abstract="true" name="GoogleMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_MicrosoftMember" abstract="true" name="MicrosoftMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_NumberOfPaidSearchAdvertisingPartnershipContract" abstract="false" name="NumberOfPaidSearchAdvertisingPartnershipContract" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="sst_CapitalizedComputerSoftwareInProgress" abstract="false" name="CapitalizedComputerSoftwareInProgress" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_AccruedRevenueShareCurrent" abstract="false" name="AccruedRevenueShareCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_ShareBasedLiabilityCurrent" abstract="false" name="ShareBasedLiabilityCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_CouponFollowIncentivePlanMember" abstract="true" name="CouponFollowIncentivePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TermLoanAndRevolvingFacilityMember" abstract="true" name="TermLoanAndRevolvingFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_DebtInstrumentAmortizationQuarterlyPayment" abstract="false" name="DebtInstrumentAmortizationQuarterlyPayment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_DebtInstrumentCovenantPercentage" abstract="false" name="DebtInstrumentCovenantPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="sst_DebtInstrumentCreditAgreementLeverageRatio" abstract="false" name="DebtInstrumentCreditAgreementLeverageRatio" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="sst_A2022RevolvingFacilityMember" abstract="true" name="A2022RevolvingFacilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_NoncontrollingInterestPaymentOnTaxReceivableAgreement" abstract="false" name="NoncontrollingInterestPaymentOnTaxReceivableAgreement" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_MarketingSegmentMember" abstract="true" name="MarketingSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_ProductsSegmentMember" abstract="true" name="ProductsSegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_CostOfRevenueNet" abstract="false" name="CostOfRevenueNet" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_AdjustedGrossProfit" abstract="false" name="AdjustedGrossProfit" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="sst_TrancheIISARsMember" abstract="true" name="TrancheIISARsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheIIISARsMember" abstract="true" name="TrancheIIISARsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheIVSARsMember" abstract="true" name="TrancheIVSARsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheIVSARsOneMember" abstract="true" name="TrancheIVSARsOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheIVSARsTwoMember" abstract="true" name="TrancheIVSARsTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheIVSARsThreeMember" abstract="true" name="TrancheIVSARsThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_TrancheISARsMember" abstract="true" name="TrancheISARsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_A2022IncentiveAwardPlanMember" abstract="true" name="A2022IncentiveAwardPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="sst_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsStrickPriceGrantsInPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsStrickPriceGrantsInPeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="sst_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustedEBITDATrailingTwelveMonthPeriod" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustedEBITDATrailingTwelveMonthPeriod" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
