Selling software using PayPal IPN as an eCommerce platform

<?xml version="1.0"?>
<configuration>
  <connectionStrings>
    <add name="LicensingDatabase" connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\Licensing.mdf;User Instance=true" providerName="System.Data.SqlClient"/>
  </connectionStrings>
  <appSettings>
    <add key="RootUrl" value="http://www.yoursite.com/"/>
    <add key="SiteName" value="YourSite"/>
    <add key="SiteEmail" value="YourSite Support&lt;support@yoursite.com&gt;"/>
    <add key="SmtpServer" value="smtp.yoursite.com"/>
    <add key="SmtpPort" value="25"/>
    <add key="SmtpUsername" value=""/>
    <add key="SmtpPassword" value=""/>
    <add key="SmtpSsl" value="False"/>
    <add key="PayPalAddress" value="paypal@yoursite.com" />
    <!-- The settings below only apply if you are using SoftActivate Licensing SDK to generate license keys
         (as opposed to getting the license keys from the LicenseKeys table -->
    <add key="LicensingSDKLicenseKey" value="SLDPW-5GEXT-MB7YY-V6AGR-PR54U" />
  </appSettings>
  <system.web>
    <compilation debug="true">
      <assemblies>
        <remove assembly="MySql.Web, Version=6.2.5, Culture=neutral"/>
        <remove assembly="MySql.Data, Version=6.2.5, Culture=neutral"/>
      </assemblies>
    </compilation>
    <authentication mode="None"/>
    <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
    <customErrors mode="Off" />
  </system.web>
  <system.webServer>
  </system.webServer>
</configuration>