In the online world, what you think is important isn’t always important. You have to remember that the lab rat — or customer — is always right. If customers have a choice of yellow and blue and tend to pick yellow, then yellow is the way to go. Immediate feedback can help drive the direction of your online marketing campaign. Try, test, and measure to determine what works and what doesn’t.
It can seem overwhelming when you think about the ever-evolving world of digital marketing. Where do you start? What are the first steps you should take when getting your feet wet in this critical area of study? In the following article, we will walk you through all the necessary steps to get you to a comfortable place of understanding what digital marketing is and how to use custom tools and strategies to your advantage?
By default, extract-key is applied to two list elements for every comparison, but if cache-keys? is true, then the extract-key function is used exactly once for each list item. Supply a true value for cache-keys? when extract-key is an expensive operation; for example, if file-or-directory-modify-seconds is used to extract a timestamp for every file in a list, then cache-keys? should be #t to minimize file-system calls, but if extract-key is car, then cache-keys? should be #f. As another example, providing extract-key as (lambda (x) (random)) and #t for cache-keys? effectively shuffles the list.