Print contributors - bloggers and others - are emerging as experts in their field. Some desire to take their messaging to talk radio to reach larger numbers of people as well as to escape preaching to the choir.
The key to being a good guest expert is to understand the needs and constraints of live talk radio. These are bounded by the host, the topic, the callers and the clock. Managing the topic is the job of the guest expert, but print or blogging experience does not automatically translate into being a super expert on live talk radio.
The pace is different, the windows of opportunity are different; there are challenges to the guest's thesis which are live and which demand responses which are live. Those responses must also be cooperative, helpful and precise or be interpreted as a dodge or poor qualifications.
On the other hand, the most articulate guest can receive those live challenges whatever they may be and respond to them live as a rite of passage and educate listeners effectively.
John Longenecker's talk radio media training is based on a decade of being an invited guest expert on hundreds of shows large and small. His grooming can fast-track a student's learning curve to sound like the expert they really are before they ever market themselves to exciting shows' producers.