I'm not sure what releasever that AMI is. You could probably just try setting it to be 6.6, rather than $release
[schmooze-commercial] name=schmooze-commercial mirrorlist= http://mirrorlist.schmoozecom.net/?release=6.6&arch=$basearch&repo=schmooze-commercial #baseurl=http://yum.schmoozecom.net/schmooze-commercial/$release/$basearch/ gpgcheck=0 enabled=1