Trailing backtick character, i.e.,
&"C:\Program Files\IIS\Microsoft Web Deploy\msdeploy.exe" `
-verb:sync `
-source:contentPath="c:\workspace\xxx\master\Build\_PublishedWebsites\xxx.Web" `
-dest:contentPath="c:\websites\xxx\wwwroot,computerName=192.168.1.1,username=administrator,password=xxx"
White space matters. The required format is Space`Enter.