Don't town visitors always give expansion materials ?

I opened the town about 3 days ago and only the first 2 visitors gave me expansion materials out of the 5 I served. Since they pay very little I wasn't even gonna do the town but I did it anyway hoping to get LEMs & BEMs. Am I doing something wrong ? What can I do to make sure I get them more frequently ? I stopped serving them cuz it feels useless at the moment. I'm only focused on money. So I don't want the extra XP if I can't get anything good in return.