There's already software houses in my business area
It may be that you operate in a market that has software houses that supply systems specifically designed for your market, but feel that your business would be better off with software written to solve your problems.
We have an IT department
You may already have an IT department but need a little help because you have a great deal of expertise in COBOL on IBM mainframes but "Joe in marketing" wants something that runs on a PC. It could be the reverse, you have a great deal of expertise in Visual Basic, but you need to work with COBOL on SCO Unix.
We don't have an IT department
Are you one of those businesses that started out using Access/Paradox/Foxpro and suddenly you're five years down the line?
You have 10 different databases and a dozen people with their own copies, each of which is slightly different, the "knocked together" queries are now taking three hours to run and your hardware supplier says you need to upgrade to SQL Server/Oracle/DB2 or PostgreSQL/MySQL but he can't help you with your applications.
Maybe your .... can handle most of your day to days needs, but you have a one-off project that is too difficult or time consuming