Mobile first is touted by some really big names in our industry. Jeremy Keith, Brad Frost, and Mr Mobile First himself Luke Wroblewski has all repeatedly pushed for a mobile first website approach.
Strategically it is the way to go.
Linear Content
By starting mobile first with your responsive website you are able to make the tough decisions about the content. Mobile first often lends itself to a linear layout model, although this is a general truth and not necessarily a rule.
The great thing about this approach is it forces you into a content hierarchy. The most important piece of content is on top, followed by the next, followed by the next. Unlike a desktop approach where you can put two pieces of content side by side for equal footing, a mobile approach means one is above the other.
How to decide your order
There are many techniques, card sorting is one of the most common. I recently came across a great article by Brad Frost who laid out what I think is a great approach to a responsive project (not just the content considerations).
Before you leave
I know, "another newsletter pitch" - but hear me out. Most JavaScript newsletters are terrible. When's the last time you actually looked forward to getting one? Even worse, when's the last time you actually read one rather than just skim it?
We wanted to change that, which is why we created Bytes. The goal was to create a JavaScript newsletter that was both educational and entertaining. 105,639 subscribers and an almost 50% weekly open rate later, it looks like we did it.
Delivered to 105,639 developers every Monday

Sdu
@sduduzo_g
This is the first ever newsletter that I open a music playlist for and maximize my browser window just to read it in peace. Kudos to @uidotdev for great weekly content.

Brandon Bayer
@flybayer
The Bytes newsletter is a work of art! It's the only dev newsletter I'm subscribed too. They somehow take semi boring stuff and infuse it with just the right amount of comedy to make you chuckle.

John Hawley
@johnhawly
Bytes has been my favorite newsletter since its inception. It's my favorite thing I look forward to on Mondays. Goes great with a hot cup of coffee!

Garrett Green
@garrettgreen
I subscribe to A LOT of dev (especially JS/TS/Node) newsletters and Bytes by @uidotdev is always such a welcomed, enjoyable change of pace to most (funny, lighthearted, etc) but still comprehensive/useful.

Muhammad
@mhashim6_
Literally the only newsletter I’m waiting for every week.

Grayson Hicks
@graysonhicks
Bytes is the developer newsletter I most look forward to each week. Great balance of content and context! Thanks @uidotdev.

Mitchell Wright
@mitchellbwright
I know I've said it before, but @tylermcginnis doesn't miss with the Bytes email. If you're a developer, you really need to subscribe

Ali Spittel
@aspittel
Can I just say that I giggle every time I get the @uidotdev email each week? You should definitely subscribe.

Chris Finn
@thefinnomenon
Every JavaScript programmer should be subscribed to the newsletter from @uidotdev. Not only do they manage to succinctly cover the hot news in the JavaScript world for the week but it they manage to add a refreshing humor to it all.