When it comes to bug hunting you need to be pragmatic. Unless you are working in the pharmaceutical industry or you offer banking services you will never be able and willing to achieve 99.9% confidence in perfection. You will not be able because development resources are limited and you will not be willing because this comes at a very high price.
How can you ensure that most of your customers receive the best possible service without your development team getting lost in the quest for perfectionism? This is the point where the Pareto principle (also known as the 80/20 rule) comes into the game. Let’s prioritize, let’s search for bugs where traffic and conversion happens. Not all bugs are created equal.
Data driven testing takes this into account. It’s the same effort to fix a piece of code which affects 80% of your customers as to extinct a bug which gets only seen by less than 1% of your visitors. Traffic and conversion data helps you in putting the right investigation areas on top of the list. Constant evaluation of the priority ranking helps you to focus on the important issues. Your customers will appreciate that.
Some bugs are dramatic and hinder the visitor to convert, others will just hurting your aesthetic perception and most bugs are somewhere in-between. Whatever you find as bugs, they are important. Even more important is the way how you address them. As long as you have limited resources and you want to drive your business further, focus on important stuff. Not every bug needs to be fixed. At least not now, maybe later …