[pgsandstrom]

Once you decide to do A/B-testing you only need to know enough about probability to know that it is very hard to guess the amount of traffic needed. That's when you google to remind yourself how to do the actual calculations.

[pja]

Knowing that you don't know how to correctly calculate the traffic required to reach a specific confidence for an A/B test makes you better than all those people who don't even know that they don't know, and just wing it.

(edit: remove multiple calculates!)