The concept here is the same as in optimizing your location. What would the type of person you want to find you enter in the “Industry” field? This can be tough because even those that work at the same company as you might list different industries here. One interesting thing is if you have upgraded to a paid LinkedIn account, your complete “Who’s Viewed Your Profile” will also include data as to which industries best represent the visitors to your profile. You might have to do some experimenting here, and not everyone uses the Industry feature to filter search results, but you should put your best foot forward and experiment in seeing how changing your industry might affect your profile views.