Even more than money sometimes people can help with the actual wedding? I.e. planning, helping to get specific things. Maybe someone has a dress, table clothes, friends with a band, friends of a florist, extra furniture for their apartment etc etc.
Also if you are lacking a specific basic thing for the wedding you may receive extra sponsorship if people are actively involved in the planing.
People on here are pretty good at getting deals
Obviously don't want to be to intrusive though.