Re: measuring results
It's good to start measuring immediately, then for when it comes to adjusting things:
Things you can adjust immediately:
- Add more keywords for search terms you are not covering yet
- Add negative keywords for search terms that you see popping-up but are not interesting for your business
- Add more ads per adgroup so that after a while you can see which one performs better
- Adjust the bids of your keywords if you're not happy with the place they're showing up on
But then there are also a few things where it's better to wait until your data is statistically significant before taking action. At least 1000 impressions would be good, but might not always be possible.
This would include you making changes based on CTR, coversion rate ... Even for changes triggered by QS I would wait a bit.
In short, deciding if you should / can make a change should depend on how trustworthy the data is you are working with. Some data you can act upon immediately, other data it's better to wait a bit.