Free the birds

When we visited Wat Sala Loi in Korat there was a man who had these birds in a cage. They were for sale. When people buy them they don't take them home. These are not pet birds, they are wild birds. People buy them to set them free. They think that by setting the birds free they will make merit.

The next day the man will be back at the temple selling wild birds again. He has caught some more. Maybe they are even the same birds. I don't think there is any merit from buying these birds. If people stopped buying the birds the man would stop catching them and selling them. The birds would always be free. What do you think?