up·sell·ing 
(ŭpsĕl′ĭng)
(ŭpsĕl′ĭng)n.
The practice of offering customers additional or more expensive products or services after they have already agreed to buy something.
upsell′ v.
- commissionaire
- commissional
- commissioned officer
- commissioner
- commissionership
- commission merchant
- commission plan
- commissural
- commissure
- commissurotomy
- commit
- commitment
- commitment ceremony
- committable
- committal
- committee
- committeeman
- committee of the whole
- committeewoman
- commix
- commixture
- commode
- commodifiable
- commodification
- commodify