Premium public records require you to pay for access, a report or a copy of documents. Information brokers, specialising in data and analytics, commonly charge for all searches and reports. Certain types of records will also attract a fee such as Police checks.
In many cases public records will be available in both free and paid forms. A free search will allow you to locate the specific record you are seeking. You can then pay for a certified copy of the record. This is common place with historical birth death and marriage certificates.
Some forms of fee based public records are designed to save a person or company time. Whilst you may be able to run the search cheaper or for free yourself, having a company perform the tasks for you can be quicker and simpler. This is especially true when you have to conduct multiple records searches. They are also often experts in the field and know exactly which searches will be of most benefit.