A/B Testing or 360 view? Identifying the type of information we are handling is the base for building decision-making scenarios with an acceptable level of risk. The type of information has nothing to do with the information source.
The information source is just a mere “provider” but is not important at all once the information is already in your information system.
For instance a Web Analytics tool could provide Behavioral information, however some of them could provide attitudinal information and it doesn’t make any change as long as you know which kind of information you are handling in every case.
If your Web Analytics tool just provide Behavioral information (all the Web Analytics tools do it) means that you will know “How are you users navigating your website” but not “Why they are navigating it that way”.
If you want to know the answer of the second question you will need a different type of information…attitudinal one.
As much different type of information you collect as clear will be the scenario for decision-making.
That is exactly what we call a 360 view, because help you understand What the users did in you website, why they behave that way, how could influence the environment that particular behavior, etc.
However, sometimes, having all the necessary information takes more time than the available and deviate you from your objective…normally increasing the benefits. So never fell in love with any model.
The most important thing is making decisions that bring you as closest as possible from you objective.
In the above mentioned example (when time constrains…more than normal 
) you could create scenarios without a 360 view…in that cases you can abuse from A/B testing or multivariate testing. Multivariate and A/B testing are techniques that allow you to identify the page or advertising that help you best achieve your goals.
You can send traffic randomly to your website testing two or more pages and measure which one is performing best, then test it in comparison with another one and so.
In a pretty fast manner you will get the optimum page or ad. Even though is important to get in mind that there is a huge difference between having or not a 360 view.
The 360 view will provide you attitudinal information which means that you will know what are your users/clients willing to see/interact/buy and you could build (using also the other type of information) the page or ad that fit best their needs.
With A/B or multivariate testing you get the best one from those you displayed to your clients/users, which doesn’t mean that is the one that fit best their needs because the test you created are based on your mental model and not on what your clients or users are expecting.