What are the pro's and con's for adapting (or failing to adapt) a companies marketing/corporate website to be responsive?

Question

Weighing up the pro's and con's, should a company invest the time, money and staff in adapting an existing site to be responsive (definition below)?

I'm after a solid argument for (or against) committing resources to achieve this task. Do the negatives of NOT making it responsive outweigh the time and effort of doing it?

(definition from wiki below :P)

Responsive web design: - aimed at crafting sites to provide an optimal viewing experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from mobile phones to desktop computer monitors).

Answer 1

Even if it's an obvious answer to this question, it is still important. Apart from the target audience answer to this question, which is also an answer, I'd go with the more future safe one.

The website don't have to be responsive in every aspect. A mobile friendly website is very important though. You need to make sure mobile users have a good experience if you want them to be positive about your site. It's best explained in an image which is 21 months old:

Imagine the figures today and tomorrow and there's your answer to every reluctant IT or Marketing manager.

Websites that aren’t mobile-friendly annoy users and that’s bad business. Consumers are doing more on mobile devices, including shopping and product research; when they do, users look for content to meet their on-the-go needs.

A recent Google survey of mobile users found that 72 percent of mobile users say it’s important to them that websites are mobile-friendly, yet 96 percent have visited a site that doesn’t work well on their device.

Almost three-quarters of respondents said they are more likely to revisit a mobile-friendly site. Users are five times more likely to abandon the task they are trying to complete if the site isn’t optimized for mobile use, with 79 percent saying they will go back to search and try to find another site to meet their needs.

Reference: 72% of Consumers Want Mobile-Friendly Sites: Google Research

Answer 2

This is more like a project management question than a ux one. Every decent company has stats regarding their traffic.

It's clear that users coming from mobile devices would benefit from a responsive design because the site would be more readable and accessible for their small screens. Simply not having to zoom in and move around the page is a big plus, and I don't think you need to show any statistical data for it, it's common sense.

If they have a huge amount of traffic coming from mobile, or from devices that have a width that is less than the size of the site in it's current form, then they are losing big time because their site is not responsive. However, if the traffic is mostly desktop, then the return on investment for implementing responsive design is low.

Another thing to consider is the design workflow that is already set up and how the designers are working in/for that company right now. They might not be used to the responsive requirements, they might not have a proper understanding of how to do the design, or the product owner/whoever makes the requirements doesn't know how to ask for responsiveness.