Most franchise programs also offer ongoing operational support from the franchisor. Support may include pooled purchasing of inventory, supplies, insurance, or other inputs into the franchised business, as well as various research and development functions. Operating support almost always includes various forms of advertising and marketing assistance. As with many other features of a franchise, the composition and quality of operating support services varies greatly from one franchisor to another. This occurs even within a single industry sector and certainly between different industry sectors. Again, careful investigation and aggressive shopping are both required for a prospective franchisee to identify a suitable franchise program offered by a franchisor with successful track record. Not every franchisor consistently delivers what it promises, and not every support service is worth its cost to the franchisee.