Millions following model company producing amusing programme (6)
I believe the answer is:
sitcom
'amusing programme' is the definition.
'millions following model company' is the wordplay.
'millions' becomes 'm' (abbreviation).
'following' is a charade indicator (letters next to each other).
'model' becomes 'sit' ('sit' can be a synonym of 'model'**).
'company' becomes 'co' (abbreviation).
'sit'+'co'='sitco'
'm' put after 'sitco' is 'SITCOM'.
'producing' acts as a link.
(Other definitions for sitcom that I've seen before include "TV series (colloq.)" , "Friends, for example" , "Amusing TV series (abbr.)" , "TV show intended to be humorous" , "Episodical TV programme" .)