I recently wrote a detailed post about this, actually: How to Hire a Good Marketer (for Startups). Though it starts with What is Good Marketing and What Skills Does a Marketer Need?, it sounds like you'd most be interested in the How do you Determine if They Have the Skills? section:
The best evidence is always just that:
evidence. If they can show the results
they specifically generated for
projects (“I increased…”, not “My
company increased…”), that’s
Some questions you may want to ask in
an interview are:
- How would you describe my company to a friend you wanted to use
- Their answer should describe benefits, from a user point
of view, rather than features.
- What are two specific types of potential users you think we could
better focus on reaching, and how? –
or – What are two specific ways you
can see our product being used, and how
should our marketing target people who
would most use it one of those ways?
- They should demonstrate an ability to make some kind of
intelligent segmentation of your
overall market into audiences that you
can create specific messages or use
specific mediums to reach.
- What trends do you see in our industry that we could tap into, to
attract more users?
- Here they should either show you that they know the scene
well, or that they’re motivated enough
to do research about it. The trends
they recommend tapping into should be
You should also take a look at the previous Answers.OnStartups question...
What's the Best Way to Find / Evaluate a Marketing Cofounder?
...and this previous OnStartups.com post...
A Geek's Guide to Hiring Marketing People.