class Country # has 'products_count' column
  ...
end

class MadeIn # has 'products_count' column
  belongs_to :country
  
  custom_counter_cache_for :country => {:made_ins_count => 1, :products_count => :products_count}
  
  # So, when MadeIn created/deleted, Country's 'made_ins_count' incremented/decremented by 1 and 'products_count' by MadeIn's 'products_count' value
  ...
end

class Category # has 'products_count' column
  acts_as_nested_set # has parent and children (!)

  custom_counter_cache_for "parent*" => {:children_count => 1, :products_count => :products_count}

  # So, when Category created/deleted, parent's 'children_count' incremented/decremented by 1 and 'products_count' by Category's 'products_count' value

end

class Brand # has 'products_count' column
  ...
end

class Product < ActiveRecord::Base
  belongs_to :category
  belongs_to :brand
  belongs_to :made_in
  
  custom_counter_cache_for :made_in => {:products_count => 1, :country => {:products_count => 1}}, :category => {:products_count => 1, "parent*" => {:products_count => 1}}, :brand => {:products_count => 1}

  # You can use nested options... it is very very useful :)

end

gem 'active_tools'

$ bundle

$ gem install active_tools