Granite countertops do require maintenance; especially since they are relatively expensive you want to get the most for your money.  Because it is porous, granite should be initially sealed and then resealed on a regular basis in order to repel water and oil based stains. 

Although lack of maintenance can make granite dull, it can be cleaned and polished by professionals to restore its shine.  To clean granite, use neutral cleaners, stone soaps or mild liquid dishwashing detergents.  It is important to avoid products containing abrasives.  Unfortunately, if granite is cracked, it needs to be removed and replaced.