The following is a great post by Tobias Zimmergren about how to change the text in the upper left of the 2013 branding very easily via PowerShell.
http://zimmergren.net/technical/sp-2013-tip-change-the-sharepoint-text-in-the-top-left-corner
Thanks Tobias, I’ve used this several times (including in our own Portal – seen below).
[code language=”powershell”]
$webApp = Get-SPWebApplication http://[your SharePoint web application]
$webApp.SuiteBarBrandingElementHtml = "Awesome Text Goes Here"
$webApp.Update()
[/code]
Note, the “SuiteBarBrandingElementHtml” can contain any text or HTML you’d like to include.
Not work in sharepoint 2016