So what is "getting-used-to" factor? If you want to get some task done using a software product, you just know how to do it as against to navigating your way through toolbars and menu items to figure out how to get a task done.
In case of consumer software product where the switching cost is almost zero, if the product is not easy to get used to, it would become an obstacle for reception of the product by consumers. If you are building a product that is a 10x better version of competing product that users are currently using, how easy are you making it for them to switch to your product. For eg: if you developing a state-of-the-art email client, will your users be able to come up to par with being familiar with your email client in less than 2 minutes after installing the product. If not, most likely users will form a first impression of your product that it is not easy to use and will simply continue using whatever they were before installing your product.
So, if you are making a product which will replace an existing competing product, one of the important criteria to keep in mind is the 'getting-used-to' factor. In this case, getting used to should be seamless.
