Is it legal for a company to require an employee to get a high percentage of customer phone numbers and email addresses?

Assuming there is no employment agreement or handbook that prohibits it, and that your daughter's employer is not asking its employees to do anything illegal (like hacking computers to get phone numbers) or unethical (like lying in order to get the information), I don't think there is any reason why the employer can't impose a quota on obtaining information from customers much like any other production quota.