Transportation is number one. Power generation and telecommunications are becoming very vital, especially if you're in the teleselling business or the telemarketing business. Technology and its availability. Financing, sites, and building availability are factors in infrastructure. The latter two can become a detriment or an asset to an area depending on the mixture.
Some states actually build infrastructures around attracting certain industries.
North Carolina is working on a program called the Global Transpark where they're making investments in a particular type of development that will attract certain multi-modal companies into their area. The availability of trained people, access to education, and competitive salaries and benefits for that industry. Finally, quality of life. Crime control, cost of living, social programs for the needy, clean environment, recreation are all quality of life factors to be considered.