phising
confirming that you are a real person for other spammers
getting personal details for identity theft and bank details for fraud.
Plenty of people out there who are unwise to these things.
Davids Mother was sending out cheques and cash to companies sending her bogus bills and threatening letters. She was losing her marbles a bit, old, frightened and being taken advantage of. When we went through her house I went through every letter and envelope carefully and found over £100. That was after finding a £10 in one envelope while David's bro was just chucking everything out.