Image by smemon87 via FlickrInterstitial isn’t a new word in marketing and advertising. You may already use the word to describe those annoying ad pages that appear instead of the content page you were expecting. In video (so I suppose TV as well) interstitial ads are ones which appear during the video play rather than at the start (pre-roll) or at the end (post-roll).
Google Instant brings us Interstitial Search Results. As a user searchers Google a series of SERPS flash by and those are our new interstitials.
When we’re judging a keyword/s then we’ll have to now consider the interstitial search results associated with that keyword. If you know that Google is prone to showing a highly eye-catching set of Universal Search in the interstitial searches results as the user types in the keyword in question then you may well view that keyword differently from one which has a less distracting, interruptive or seductive interstitial search results.