Hi Matthew,
Disclaimer; I have not tested this solution on an actual installation of Dynamics CRM 2013.
Whether or not the marketing tab is displayed for a user is controlled by the user's read access to the entities within the marketing tab.
If the sales personnel have had all rights revoked from the "Marketing list" entity for instance, you can run a check on this in the Sitemap XML to hide the entire marketing tab if the user does not have "read" access to marketing lists.
I would ask of you to attempt the following:
Export the current Sitemap of your solution as an unmanaged solution. For step-by-step guide to this, see msdn.microsoft.com/.../gg309424.aspx
Back up the .zip-file somewhere safe.
Open the file "customizations.xml" from within the .zip-file you exported from CRM with a simple text editor (Notepad/Notepad++ for instance).
Navigate to the marketing section of the Sitemap. If your Sitemap is completely standard, it should look like this:
<Group Id="MA" ResourceId="Area_Marketing" DescriptionResourceId="Marketing_Description">
<SubArea Id="nav_lists" DescriptionResourceId="MarketingList_SubArea_Description" Entity="list" GetStartedPanePath="Marketing-Lists_Web_User_Visor.html" GetStartedPanePathAdmin="Marketing-Lists_Web_Admin_Visor.html" GetStartedPanePathOutlook="Marketing-Lists_Outlook_User_Visor.html" GetStartedPanePathAdminOutlook="Marketing-Lists_Outlook_Admin_Visor.html" />
<SubArea Id="nav_minicamps" DescriptionResourceId="Quick_Campaign_Description" Icon="/_imgs/ico_18_minicamps.gif" Entity="bulkoperation" GetStartedPanePath="Quick-Campaigns_Web_User_Visor.html" GetStartedPanePathAdmin="Quick-Campaigns_Web_Admin_Visor.html" GetStartedPanePathOutlook="Quick-Campaigns_Outlook_User_Visor.html" GetStartedPanePathAdminOutlook="Quick-Campaigns_Outlook_Admin_Visor.html" OutlookShortcutIcon="/_imgs/olk_4400.ico">
<Privilege Privilege="AllowQuickCampaign" />
</SubArea>
</Group>
I would like you to add the following line within the <SubArea> tag with ID "nav_lists": <Privilege Entity="list" Privilege="Read" />
The marketing section of the Sitemap should then look like this:
<Group Id="MA" ResourceId="Area_Marketing" DescriptionResourceId="Marketing_Description">
<SubArea Id="nav_lists" DescriptionResourceId="MarketingList_SubArea_Description" Entity="list" GetStartedPanePath="Marketing-Lists_Web_User_Visor.html" GetStartedPanePathAdmin="Marketing-Lists_Web_Admin_Visor.html" GetStartedPanePathOutlook="Marketing-Lists_Outlook_User_Visor.html" GetStartedPanePathAdminOutlook="Marketing-Lists_Outlook_Admin_Visor.html">
<Privilege Entity="list" Privilege="Read" />
</SubArea>
<SubArea Id="nav_minicamps" DescriptionResourceId="Quick_Campaign_Description" Icon="/_imgs/ico_18_minicamps.gif" Entity="bulkoperation" GetStartedPanePath="Quick-Campaigns_Web_User_Visor.html" GetStartedPanePathAdmin="Quick-Campaigns_Web_Admin_Visor.html" GetStartedPanePathOutlook="Quick-Campaigns_Outlook_User_Visor.html" GetStartedPanePathAdminOutlook="Quick-Campaigns_Outlook_Admin_Visor.html" OutlookShortcutIcon="/_imgs/olk_4400.ico">
<Privilege Privilege="AllowQuickCampaign" />
</SubArea>
</Group>
Alternatively you could try putting the <Privilege> tag directly above the <SubArea Id="nav_lists"[...]> -line. As I said I haven't tested this in an actual environment, but in theory it should require the "read" privilege to the "list" entity (Marketing lists) in order to show the marketing tab.
Save customizations.xml, zip it together with [Content_Types].XML and solution.XML and upload the .zip-file as an unmanaged solution.
I hope this helps! Good luck.
Regards,
Rasmus