<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2011-06-08</periodOfReport>    <notSubjectToSection16>0</notSubjectToSection16>    <issuer>        <issuerCik>0001402305</issuerCik>        <issuerName>SuccessFactors, Inc.</issuerName>        <issuerTradingSymbol>SFSF</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001492475</rptOwnerCik>            <rptOwnerName>SMITH HILLARY B</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>C/O SUCCESSFACTORS, INC.</rptOwnerStreet1>            <rptOwnerStreet2>1500 FASHION ISLAND BLVD, SUITE 300</rptOwnerStreet2>            <rptOwnerCity>SAN MATEO</rptOwnerCity>            <rptOwnerState>CA</rptOwnerState>            <rptOwnerZipCode>94404</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isDirector>0</isDirector>            <isOfficer>1</isOfficer>            <isTenPercentOwner>0</isTenPercentOwner>            <isOther>0</isOther>            <officerTitle>General Counsel</officerTitle>            <otherText></otherText>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2011-06-08</value>            </transactionDate>            <deemedExecutionDate></deemedExecutionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>M</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>                <footnoteId id="F1"/>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>3250</value>                </transactionShares>                <transactionPricePerShare>                    <value>23.01</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>A</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>3250</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2011-06-08</value>            </transactionDate>            <deemedExecutionDate></deemedExecutionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>                <footnoteId id="F1"/>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>3250</value>                </transactionShares>                <transactionPricePerShare>                    <value>32.89</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>0</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>    </nonDerivativeTable>    <derivativeTable>        <derivativeTransaction>            <securityTitle>                <value>Stock Option (right to buy)</value>            </securityTitle>            <conversionOrExercisePrice>                <value>23.01</value>            </conversionOrExercisePrice>            <transactionDate>                <value>2011-06-08</value>            </transactionDate>            <deemedExecutionDate></deemedExecutionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>M</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>                <footnoteId id="F1"/>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>3250</value>                </transactionShares>                <transactionPricePerShare>                    <value>0</value>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <exerciseDate>                <footnoteId id="F2"/>            </exerciseDate>            <expirationDate>                <value>2020-06-15</value>                <footnoteId id="F2"/>            </expirationDate>            <underlyingSecurity>                <underlyingSecurityTitle>                    <value>Common Stock</value>                </underlyingSecurityTitle>                <underlyingSecurityShares>                    <value>3250</value>                </underlyingSecurityShares>            </underlyingSecurity>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>58500</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </derivativeTransaction>    </derivativeTable>    <footnotes>        <footnote id="F1">The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on April 29, 2011.</footnote>        <footnote id="F2">The option vested as to 25% of the shares on May 17, 2011 and vests as to 1/48th of the shares at the end of each full month thereafter.</footnote>    </footnotes>    <remarks></remarks>    <ownerSignature>        <signatureName>/s/ Hillary B. Smith</signatureName>        <signatureDate>2011-06-09</signatureDate>    </ownerSignature></ownershipDocument>