One great advantage of a blinking light is that it will run longer on a given battery than a steady light, thus improving your chances of being detected considerably.

Actually, my experience has been that initial contact is typically made by voice or sound, rather than directly by light. This has been in mountainous terrain, primarily. But if you are shining a light in a high spot, your light may well be seen by another search party at a distance, who would then alert the group closest to you. Making as much noise/light/commotion as possible is always a good thing.