As the old saying goes, trouble doesn't come from what you don't know, but what you think you know that ain't so. This truism of life applies as much to online retail as anything. There are some major assumptions that drive retailer strategy that don't have a basis in reality, according to some recent analysis from McKinsey & Company.

E-commerce, mobile in particular, is increasingly a driving force in retail. For example, look at this data from Internet Retailer, which shows a steady increase in the share of how consumers gain access to online retail. Digital shopping is not only important to retailers, but to anyone trying to sell their products through a distribution channel. If your resellers aren't correctly handling e-commerce, they either need to change or you need to consider other retailers.

According to some recent McKinsey survey research, there are four e-commerce myths that keep retailers heading in the wrong direction. Move past them, and you're likely to position yourself more effectively going forward.

Myth 1: Depend on apps

Apps are great and often seen as the major tool of online interaction. Retailers are sure apps will bring in new customers. Actually, they can be good for loyal customers. But there are just too many of them popping up and people are becoming reluctant to install one to do some shopping. To gain new customers and satisfy many existing ones, make sure you have a mobile-friendly site. However, given Google's recent moves, be sure to create an adaptive design that can work for mobile or desktop/laptop. The search giant has been giving lower scores to companies that maintain separate mobile sites.

Myth 2: Be sure to have cool features

Marketers and technologists do have a common meeting ground: They love flashy features when it comes to e-commerce sites. But it turns out that customers don't care so much. Give them something that loads really fast. Speed was 60 percent more important to them than having video. They want smooth checkout and ease of adding or deleting products from a shopping cart. Navigation is a big frustration on mobile shopping sites, so be sure it's clear and effective. I'd also point out that making it difficult to see the full cost of something, including what shipping might be, is one of the leading causes for shopping cart abandonment. Don't try to trap them as the price for getting information.

Myth 3: Showrooming is a killer

Brick-and-mortar retailers hate the thought of people coming in, looking at products, and then checking online for a cheaper source. And that's understandable. However, people have always comparison shopped, and it's not as though the retailers don't get significant amounts of business. According to McKinsey, most people end up buying at the retailer and 58 percent do at a physical store, most at the one where they first saw the item. Price is important, but so are convenience, availability, and the ability to easily talk to someone if there's a problem. Don't be so afraid of competition that you forget your own natural strengths and try to discourage mobile.

Myth 4: Digital is all about self-service

Some retailers are so in thrall to the idea of reducing costs that they view everything in that light. E-commerce and mobile become ways for customers to find and order what they want, reducing the need for in-house staff. Technology might help reduce the need for people to do inventory or checkout--maybe, though it's foolish to underestimate how much help even these areas might need--but don't assume that consumers are self-sufficient. Sixty percent of mobile shoppers interviews thought that store staff could use technology to better help consumers "find products, explain options and features, order out-of-stock items, and so on." Remember to use technology in all the ways you can to improve the shopping experience, not to make it even more inhuman and bleak.