Conversation so far:
What was Horace Plunkett trying to accomplish?
Horace Plunkett set himself to bring together people of all political views for the promotion of the material prosperity of the Irish people.
what did Horace Plunkett do to help the movement?
Horace Plunkett opened the first creamery in Dromcollogher, County Limerick.
what project was Horace Plunkett involved in?
As early as 1894, when his campaign reached a size too big to be directed by a few individuals, Horace Plunkett founded the Irish Agricultural Organisation Society.
What did Horace Plunkett's Irish Agriculture Organisation Society do?
Horace Plunkett's Irish Agriculture Organisation Society became the powerhouse of co-operation.

Question: how was this beneficial?
Self-contained rewrite: how was Horace Plunkett's Irish Agriculture Organisation Society beneficial to farmers in Ireland?