When using LinkedIn for business, it is important that you use a profile picture on your account. If you do not have a profile picture, people are less likely to connect with you and less likely to interact with you. As LinkedIn users, we like to see a face with the account. Otherwise, we feel we just don't know this person. If our photo is on the profile, it gives people a place to start to get to know you. It's friendlier and more open feeling to the viewer.
If you would like to learn more about using LinkedIn for business, check out LinkedIn 101.