Tradio is a type of talk radio show format where listeners call in to buy or sell items. The concept is analogous to classified ads in local newspapers.
"Tradio" is a portmanteau of "trade" and "radio". The format is also often called Swap Shop, Buy Sell or Trade, Biz Baz, or Trading Post.
Most tradio programs follow a similar format to each other. Callers are given a studio line in which they can call in and advertise, for free, a limited number of items for sale, or request an item to purchase from another listener. The caller then gives a phone number so that other listeners can contact the person for further information. Since the increased prevalence of e-mail and other electronic media, most stations permit the sending in of items to sell via e-mail or fax, though due to regular and/or identity theft concerns some stations will assign a code number to anonymize the transaction and keep identifying information off the air. Most stations also permit listeners to send lists of items through postal mail. Tradio programs are particularly associated with the full service format; tradio was commonly found on Independent Local Radio in the UK when it used a similar format (up to around 1990).
There are usually some limits to what can be bought and sold through tradio programs. Most stations stipulate that only individuals, and no businesses, may use the tradio service, since the financial security of these small stations usually relies on the advertising dollars from these businesses. Federal regulations prohibit the sale of firearms through these services; real estate is also usually not allowed on tradio programs. Restrictions on the sale of automobiles varies from station to station.
The name "tradio" does not apply to any one particular program and there are no national or syndicated tradio programs. It is technically not a franchised format, either.
Typically tradio and similar programs are only heard on small, rural stations; KDKA in Pittsburgh, Pennsylvania is the largest market with a tradio program, airing weekly on Saturday afternoons. A similarly-styled program titled Wheelin' and Dealin' with Dave Ramos also airs during the weekends on WTAM in Cleveland, Ohio (but is not in a regular timeslot). In smaller markets, tradio programs can air daily. The smallest radio station in America that airs a Tradio program is KEDU in Ruidoso, New Mexico; the program is heard Monday through Friday at 9:30am.
Various Tradio programs have been the target of prank phone calling by The Howard Stern Show's Richard Christy and Sal Governale.