Why make the switch?
By moving from spreadsheets and desktop databases you can immediately work collaboratively within your entire business. This immediately removes human error and multiple copies of the same, but slightly different, data being distributed around departments.
Ultimately there are limitations to how far spreadsheets and desktop databases will get any business. Eventually growth will become impossible and a crunch will inevitably force a change. It's always better to make the change while the business has capacity to cope rather than waiting for the inevitable to happen...
By removing numerous copies of the same data, every member of staff works from the same understanding. This removes misunderstandings, errors and improves bottom line profitability.