Although difficult to achieve randomizing the data of a test can increase it's value. Imagine a test as trail through a forest, once created with set data each run follows the same trail, not exploring the unknown parts of the forest. Bugs in this metaphor will often be found in the unexplored areas. Changes in the data used by the test can expand the coverage of the test and increase it's value.
In a similar fashion when tests are executed in random or the test actions themselves execute in a random order (see model based testing) additional value can be derived from the same tests.
The easiest way though to increase the ROI of your automation suite is to change the SUT. This could mean running your test against:
- Different operating systems. Especially valuable now in mobile testing where operating systems are changing more rapidly.
- Different browsers.
- Different devices.
- Different integrated environments/components.
As a manual tester I've done browser upgrades and never has my desire to come into work been dampened to the same extent. So a side benefit to executing automation against SUT is that it reduces the mindnumbing arduous tasks that need to be completed by manual testers.