You wouldn’t have any idea of who Sandra Bland was if it wasn’t for media momentum. And no one would be investigating her case. And she would have zero shot at justice.

Bland was pulled over for a routine traffic stop in Waller County and was found hanging dead in her cell three days later.

These things happen — maybe not this weird — but the unfortunate truth is they happen all the time, and have been happening for what seems like all time. But what’s different here is that Bland was pulled over during a media moment when police brutality from Ferguson to Staten Island to Skid Row is in the news. And so is the topic of jail conditions. And so are police body cameras. And so is race. It’s the merging of these media conversations that put the disturbing story of Sandra Bland onto the headlines and into your social media feed.

It’s how it got here.

On it’s own, what happened in that cell is not enough. An event alone is rarely enough to get our attention, and sometimes that attention is the one thing that can change the course of a story — in this case, the course of the story was certain to be another black person who died under unusual circumstances and was forgotten by everyone except her family and friends who wondered why (but weren’t surprised that) no one gave a damn.

When you need a story to get attention, you need media momentum. Media momentum moves reporters to continue an ongoing storyline. Media momentum, like a popular meme, keeps people tweeting and Facebooking about a conversation that’s already started. Media momentum makes the stories easier to write because we share a common set of facts, and often a common shorthand with which to discuss those facts. Media momentum means more traffic to a story. No one wants to read your think-piece on a topic they’re not already thinking about. No one wants to talk about humidity during a blizzard. But media momentum extends beyond journalists and readers. It can change laws. It can change attitudes. It can even pressure a prosecutor to focus on a case they want to ignore. Media momentum can put people on magazine covers, or it can just as easily put people in jail.

Want to know how important momentum is? Just ask the activists who pushed the same-sex marriage cause for years until it started rolling. And that story provided the perfect metaphorical lede to the Caitlyn Jenner story. Ask the people who have been pushing for legalized marijuana and an easing of drug laws how much media momentum changed the course of that story.

Of course, those were stories that would have had some attention anyway. Sandra Bland’s wasn’t. There were many things that went wrong last week. But only one of them fit perfectly into a storyline that already had momentum.

Top of meme is top of mind.

Did you hear about the stampede that killed 27 people during a clothes giveaway in Mymensingh last week? Probably not. And I’m not saying you should have. But under different circumstances, with slightly different timing, that could have been the biggest story of the week.

When it comes to studying this kind of media momentum, there are lessons about marketing, about raising awareness, about fighting for a cause. And in this case there are lessons about the case of Sandra Bland. Because of the momentum, you care about her story, and her death has a shot at getting the legal and social attention it deserves.

What causes media momentum? If we knew the exact formula, it would be repeated so often it would be rendered obsolete. But there are clues. If you arrest a couple of journalists (as happened at the Ferguson Burger King), you’ve got a decent shot. If you’re a public figure who is remarkably offensive, it can often work (bad hair helps).

Want to get some media momentum this week? Well, if you’ve considered a jail escape, this is your moment. If you’ve got a story about online trolls or questionable editorial ethics, lay it on us. If you’re an otherwise beloved celebrity who prefers his sex to be with limp, motionless, and often unconscious women, you can get some immediate headlines right now. And if you’ve ever had the urge to deflate or otherwise alter a sports ball or to do something as ridiculous as awarding a soccer tournament to a country where temperatures will be 120 degrees, for goddsakes, do it now.

Of course, for Sandra Bland’s family, there was no right time for her untimely death. But for any chance at justice, the timing may have, sadly, been perfect.

To track all the stories that have momentum, or at least should have some, get Dave Pell’s NextDraft — The Day’s Most Fascinating News.