We are still the largest in the cities which means that in other parts of the country you may not get an answer to an ad as quickly. All users are private individuals so it is based on someone wanting to advertise and someone wanting to pick up in your area.
You do usually get several to very many suggestions for retrieving what you have advertised in just a few minutes. If you do not receive a request for help, you have probably set a too low payment.
In the first instance, try to increase the payment and see if there are any suggestions! (You only pay when you get help so it's worth a try!)