How do you tell if he/she is a great marketing candidate?

What are the methodologies you use to determine if a person would make a great marketer?

For instance, I may be looking for someone who has great instinct about what the market wants and able to implement the tactics very well. How can I dig out such qualities in a candidate?

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
excellent.

Some questions you may want to ask in
an interview are:

• How would you describe my company to a friend you wanted to use
  it?
  
  • 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 people-focused.

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.

What I'd want to know:

• What do you think are the three most essential elements of success in marketing? (My favorite interview question, "If you had a marketing intern working for you and they asked you for three pearls of wisdom to help them learn about marketing, what would those pearls be?)
• What experience do you have in our specific product/service domain? What experience do they have with your target audience? Give examples of successes in this domain/audience.
• What's your process for creating a marketing plan? What are the important elements of a marketing plan? (Personas, key messages, target audience, competitive landscape, market trends, measurable objectives...) Have them do a simple outline of what's included in a marketing plan.
• What would be your process for figuring out a marketing strategy for our product/service?
• What areas of marketing (e.g. direct marketing, online marketing, social marketing...) do you consider your strongest and which do you consider your weakest? Give examples of successful marketing initiatives within your strengths.
• What trends do you think are most important in the marketing world right now and how do you factor them into your planning and execution?
• What trends do you know of in our industry that we might be able to take advantage of and leverage?
• What tools do you use for analytics and tell me how you measure the success and ROI of your efforts.
• From what you know of our company, what would you say are some opportunities that jump out at you? What would be some areas of concern?
• Tell me about your experience and successes within the online and social media areas.
• What are a couple of your most successful marketing initiatives? What are a couple of your least successful marketing initiatives?
• Why do you want to work at this company? Why are you crazy enough to want to work at a startup?

Those are a few thoughts.

Best of luck,