i feel 518 can capture more people on the return route if
commuters are convinced they can have a definite seat with DDs
deployed..
even for myself, i only take 518 from far east plaza.
all other stops, i wouldnt risk it. 
Yeah, i mean if they take the idea from why peope are willing to
pay the higher fares for Premium services and they get DDs with
more seats in return, it should apply to 518 too.
I know Premium kinda has different rules from 518 cause of the
no-standee rule for Premium? But still, I don't think anyone will
want to pay $2 or more to board 518 and stand all the way from
Marina all the way to Pasir Ris. 