You can leave your pets in their familiar environment.  Keeping to their normal routine greatly reduces stress.

Your homesitter can take on household responsibilities such as: taking care of your pets (providing medication, exercise and diet), performing general maintenance (including pools, lawns, etc.), and, in general, making sure that everything runs smoothly just as if you were at home.

Burglary and vandalism are often deterred by the sheer presence of someone at the property. Sitters provide a general presence in your absence to discourage intruders; collecting mail, answering the phone and providing light garden care.