The Importance of Flexibility in Web Development

You've got to make a lot of assumptions and you need to test them. There are devices released now, which weren't here a year ago. If you've been in it for a year, when you started your project, it's not the same as it is now. You're going to have to keep on analyzing, keep on testing, be prepared to tweak and change. And maybe add, add break points or change break points over time as you learn more about your site's usage or the site's usage changes.