Answer:
A paid circulation publication is one you pay to receive. In general, anyone can receive these magazines: if you send Time Magazine twenty bucks and your address, Time magazines will start to appear in your mailbox.
Controlled circulation publications are ones you have to qualify to receive, and according to US Postal Regulations you must requalify every year. For instance, there are magazines for used car dealers. Only used car dealers can get them because the advertisers are targeting the ads at people who are likely to buy. Most of these magazines are free to the reader.