>Some ideas are obviously good
Are they? Of course everyone thinks their ideas are "obviously good", but testing often proves otherwise. That's the whole point of it.
Are they? Of course everyone thinks their ideas are "obviously good", but testing often proves otherwise. That's the whole point of it.
Using your example of "obviously good", lets say something seems "obviously good", so you launch it, and after a week, you see that it converts worse or better. That's an A/B test, where A is before the change and B is what is after. You don't need software for that, you don't need to do on-the-fly A/B testing, you can just launch.
Given a site has existed for a while, it has a pretty known A for most things you'd want to test. Doing A/B tests on small elements seems may indeed not be worth the extraneous costs of time etc.
Exceptional growth doesn't happen because you're great at a/b testing. It happens when your team is good at decision making period.