Balance My Aircraft
Where the aircraft is far from fully laden this is usually facilitated by seat allocation so that on take off the balace is within limits. However before take-off an announcment is made requesting that passengers stay in their allocated seats until after take-off when they are permitted to "spread themselves around" so to speak. On two recent flights to Capetown with Virgin the centre economy cabin had dozens of empty seats whilst the Premium Economy was "choc a bloc". After take-off many of the crowded PC passengers came back to the Economy section. Made us feel good at just having paid economy rates for plenty of space.