The person who asked this is an editor. Many actors have postcards, (their headshot photo) that they send when they have announcements or to stay in touch.
Postcards are one way to stay in touch with people. They are a more costly way. I say that because you have to pay to have them printed and mailed. Many people's follow-strategy is email, which is free. That said, emails aren't always opened and postcards are usually seen. You have to decide if the investment is worth it.
Two things I want to address:
1. Why the follow up postcard after sending the resume and making the phone call? Is this a "cold-call" resume sending/call/postcard? If it's cold resume, the postcards are just as cold. The only difference is that after a resume and a phone call, the postcard would be the 3rd contact from you. Still, you know my feelings about putting a large percent of your "work" into pursuing cold leads. I'd rather see you strategically go after 10 jobs than pursue 100 jobs cold. You'll have better results.
2. What to put on a postcard? The same contact info you'd have on a business card and resume and then you have more freedom with the image. Perhaps, something that is unique to you and what you do, something personal (a cute picture of "you" in an edit bay with "your dog"), or a beautiful image that they would put up to look at. My allergist's postcard, to remind me it's time to come in, is a picture of a desert island with a palm tree and a clear blue ocean surrounding it. I have this postcard up in various locations and think of him, and my clear sinuses, every time I see it.
For more tips and articles by top entertainment industry career coach, The Greenlight Coach, visit www.theGreenlightCoachBlog.com