Hello Merryll,
and also you need to add ip route-cache flow under every interface you want to monitor !
For some years netflow could only monitor incoming traffic on monitored interfaces.
Now, it is possible to have sampling, egress accounting on PE-CE links, aggregation-cache (data aggregated on the router before export this is version 8).
And customizable export template with netflow version 9.
see
http://www.cisco.com/en/US/docs/ios/12_2/switch/configuration/guide/xcfnfov.html
Hope to help
Giuseppe