Whether it be a raise, promises or emotion-filled appeals, is this display realistically based on your value to the firm, or the cost and inconvenience in your replacement. While the surface may exude warmth and enthusiasm, internally the company executives are often bitter and resent have their hand forced in such a manner. Rather than raise the status of the employee, they may take measures to lessen that individuals value within the organization. They will change, really, they said they would. An integral part of the counter-offer is to discover the source of discontentment and offer guarantees that these issues will be resolved.
Promises are easy to give, much harder to deliver.
Policy and procedure changes, including promotions are generally multi-level and slow moving, often taking a back seat to the day to day priorities of business profit and operation. Examine closely the reasons why you chose to resign and review the firm's track record in making similar changes. I haven't started, so there really is no commitment. When a company has an offer accepted, they fully expect an employee to honor that commitment. Remaining candidates are released, internal announcements made, and benefits plans, payroll, etc. administered.