iterate_customers.rb

require 'stripe'

Stripe.api_key = "sk_your_API_key"

customers = Stripe::Customer.all(:limit => 100)

customers.each do |customer|
	puts customer.id
end

while customers.has_more do 
	customers = Stripe::Customer.all(:limit => 100, :starting_after => customers.data.last.id)

	customers.each do |customer|
	  puts customer.id
	end
end