im not sure how far into this im allowed to go, but here is what ive found
marketplace downloads cab to a certain directory (names file MKP followed by 6 hexadecimal caracters), then installs cab and creates a setup log file which both get deleted along with the cab. here is the log file it creates when installing facebook app:
Code:
<wap-provisioningdoc><characteristic type="Install"><parm name="InstallPhase" value="install"/><parm name="OSVersionMin" value="5.2"/><parm name="OSVersionMax" value="6.99"/><parm name="BuildNumberMin" value="0"/><parm name="BuildNumberMax" value="-536870912"/><parm name="AppName" value="Micro_Facebookfo_MRnzUunn9kWxtZjoksR4dg"/><parm name="InstallDir" value="\Program Files\Facebook" translation="install"/><parm name="NumDirs" value="4"/><parm name="NumFiles" value="12"/><parm name="NumRegKeys" value="1"/><parm name="NumRegVals" value="2"/><parm name="NumShortcuts" value="1"/></characteristic><characteristic type="FileOperation"><characteristic type="\Windows" translation="install"><characteristic type="MakeDir"/><characteristic type="zlibce.dll" translation="install"><characteristic type="Extract"><parm name="Source" value="00zlibce.001"/></characteristic></characteristic><characteristic type="fbservice.dll" translation="install"><characteristic type="Extract"><parm name="Source" value="FBSERV~1.002"/></characteristic></characteristic><characteristic type="facebook.exe.0409.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.006"/></characteristic></characteristic></characteristic><characteristic type="\Program Files\Facebook" translation="install"><characteristic type="MakeDir"/><characteristic type="FacebookGraphics.dll" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.003"/></characteristic></characteristic><characteristic type="facebook.exe.0407.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.004"/></characteristic></characteristic><characteristic type="facebook.exe.0408.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.005"/></characteristic></characteristic><characteristic type="facebook.exe.040C.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.007"/></characteristic></characteristic><characteristic type="facebook.exe.0410.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.008"/></characteristic></characteristic><characteristic type="facebook.exe.0413.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.009"/></characteristic></characteristic><characteristic type="facebook.exe.0415.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.010"/></characteristic></characteristic><characteristic type="facebook.exe.0C0A.mui" translation="install"><characteristic type="Extract"><parm name="Source" value="FACEBO~1.011"/></characteristic></characteristic><characteristic type="facebook.exe" translation="install"><characteristic type="Extract"><parm name="Source" value="facebook.012"/></characteristic></characteristic></characteristic><characteristic type="\Windows\Start Menu\Programs" translation="install"><characteristic type="MakeDir"/><characteristic type="Facebook.lnk" translation="install"><characteristic type="Shortcut"><parm name="Source" value="\Program Files\Facebook\facebook.exe" translation="install"/></characteristic></characteristic></characteristic></characteristic><characteristic type="Registry"><characteristic type="HKCU\Software\Microsoft\Facebook"><parm name="Login" value="AAA=" datatype="binary"/><parm name="UserActionPublished" value="0" datatype="integer"/></characteristic></characteristic></wap-provisioningdoc>
nowhere there does it talk about installation locations or anything. i already had it installed and have no idea what it did to the version i already installed via cab