Yep I spend like at least 10 min wondering should I make it a preference or another column in the database. I went for a column just for coupon codes being a such very common case that I thought it would be cheaper (faster) to have it as column than as a preference. Would you think it would be cheaper as a column? I would be ok with both I guess. Please let me know and I could remove the migration and go for a preference instead.