Some have asked if such interviews are even possible. It used to be that they weren't, but on Sept. 26, 2005, the law was amended to make it possible.
Authority for a preliminary interview at the discretion of the Examiner is found in 37 C.F.R. 1.33(a)(2):
An interview for the discussion of the patentability of a pending application will not occur before the first Office action, unless the application is a continuing or substitute application or the examiner determines that such an interview would advance prosecution of the application.So yes, it is possible.
But how can you do this before the first office action, when you don't even know who the examiner is? No problem! You can simply call the PTO and ask who the examiner is. I just did this recently for a patent I filed last year and was given the name and phone number of the examiner after providing the serial number of the application.
Now the examiner may not be willing to grant a preliminary interview - depends on the case and the person. And if they do grant a preliminary interview, they may request some additional info from you such as a general statement on the prior art, a list of up to three references of "closest" prior art, and an explanation of your novelty over these references. That possibility was raised by the PTO in a "PTO Day" presentation in 2005. See the bottom of page 8 in www.ipattorneyfirm.com/forms/PTOdayArticleNAPP.pdf for a summary of a PTO presentation where they stated that they may ask for additional info in a preliminary interview.
Will a preliminary interview really help? From my personal experience, I know that face-to-face interviews in general are a powerful tool in helping to expedite examination, though it will take some time to see how much traction preliminary interviews afford. I think that if the examiner is willing, it could save you many months of prosecution time and perhaps even an extra continuation fee. If you can afford to wait, fine. But if time is of the essence, think about a preliminary interview to help deal with KSR and otherwise expedite examination.