The phrase 'mainly business' is correct and usable in written English.
You can use it when referring to a particular activity or focus as being mainly (or primarily) concerned with business. For example: "He traveled to San Francisco mainly for business; he met with new clients and discussed potential partnership opportunities."
Probably mainly business people and holidaymakers bound for exotic destinations.
But for mainly business reasons, newspapers will increasingly work in harness with nonprofits.
Its members, which are mainly business schools in America with a smattering of international institutions, reported mixed results for 2012.
Black cars are essentially small-scale limousines that serve mainly business customers who pay with vouchers or credit cards rather than cash.
At the time, according to Mr. Conteh, fewer than 10,000 people living in Congo — mainly business people, foreigners and government employees — had mobile handsets.
The Asociación Civica Centro International San Diego (ACCISD) oversees the International Centre, a mainly business district north of Bogota's colonial centre which saw rapid urban development in the 1960s.
Friedman, Ellis, which does mainly business-to-business advertising, had taken on the project because it was eager to land consumer brand accounts, Mr. Rogan said.
Established in 1991, the bank invests in mainly business-sector projects in Eastern and Central Europe and Russia as part of a mandate to foster economic and political change.
But mainly, businesses hire new graduates as an investment, said Dan Black, Americas director for campus recruiting at Ernst & Young.
Since 1994, around 55,000 large consumers of electricity (mainly businesses, but also schools, hospitals and so forth) have been able to choose their supplier.
New smartphones like the touch-screen Storm or high-end Bold were attracting new sales, the company said, but existing customers, mainly businesses, were not upgrading as frequently as expected, crimping profit margins.
