Distinguish Between Sectional and Promotional Pressure Groups 

Sectional groups seek to represent the common interests of a 
particular section of society. As a result, members of sectional 
groups are directly and personally concerned with the outcome of the 
campaign fought by the group because they usually stand to gain 
professionally and/or economically. Trade unions, employers' 
associations and professional bodies are all sectional groups and 
membership is usually restricted. Promotional groups endeavour to 
promote a particular cause, and for this reason are sometimes called 
'cause' groups. They are not self-interested in that the achievement 
of their objectives is not necessarily of direct professional or 
economic benefit to the members of the group. Examples of cause groups 
are Shelter, Campaign for Nuclear Disarmament (CND) and Greenpeace. 
Because cause groups aim to promote a cause - which might potentially 
be supported by everybody, regardless of their profession or economic 
position - membership is not usually restricted.