JONAH BERGER: A way to
make this video viral?

We could make it more
emotionally arousing.

Or we could play really
loud or exciting music.

SPEAKER: Let's remix it.

[CLUB MUSIC]

JONAH BERGER: I could
say something really

provocative or controversial.

Everything Gladwell
said is wrong.

People want to hear the rest
of the video to figure out why.

Because controversy
encourages discussion, right?

It gets people to share things.

I'm Jonah Berger.

I'm a professor of marketing
at the Wharton School

and author of Contagious,
Why Things Catch On.

The book is Contagious,
Why Things Catch On,

and it's all about how
companies, individuals,

and organizations
can get word of mouth

to help their products
and ideas become popular.

I see life as a laboratory.

You can look around and
see people doing something

and wonder, well,
why does that happen?

And my job as a psychologist
or as a consumer psychologist

is to understand
those questions.

There's a guy who follows
me on Twitter who's-- he has

a reasonably large following.

And [INAUDIBLE] he was like,
oh, can I get that deal?

Because I mentioned on Twitter.

Like some people are really,
really excited about this.

And so I think this
definitely has social currency

for some people.

I think other people are
going to feel like this.

LAINIE HUSTON: Going viral
has been a concept that's

happened since ancient times.

It isn't something
that is new just

because Twitter and Facebook
are now tools that we can use.

ALEX CHAHIN: It's a science.

It boils down to several
distinct discrete variables

that you can pull and toy with
in order to make something

have a greater success
of being viral.

JONAH BERGER: I was in college,
and as grandmothers often do,

my grandmother would send
me newspaper articles.

And one summer, she
sent me an article

about a book called
The Tipping Point.

It brought together psychology,
and sociology, and marketing

in a way that had never really
been brought together before.

But it wasn't necessarily
backed up with hard data.

It was a good amount of opinion
and correlational evidence.

But as we all know,
correlation doesn't necessarily

equal causation.

Why do people talk
about and share things?

Why are certain things
shared more than others?

That's not even in
The Tipping Point.

There's no section
on what makes things

more viral or more talkable.

And so I really started
to wonder, well,

why do we share some
things rather than others?

So Rebecca Black's
song has been called

the worst song of all time.

[REBECCA BLACK, "FRIDAY]

REBECCA BLACK: (SINGING)
It's Friday Friday

Gotta get down on Friday

JONAH BERGER: Yet even
though it's so bad,

it's gotten over
300 million views.

And so lots of
people wonder, well,

why is this song that
everybody hates doing so well?

And so if you look at
the data, you actually

see something sort
of interesting.

You see a spike every week
on a certain day of the week.

And when you look at it closely,
you notice that it's Friday.

REBECCA BLACK:
(SINGING) Thursday

Today it is Friday

JONAH BERGER: So this
song is equally bad

every day of the week.

It's equally bad Monday,
Tuesday, Wednesday, Thursday.

But Friday is a ready
reminder, a trigger

to make us think
about that song.

REBECCA BLACK: (SINGING)
through the weekend

JONAH BERGER: So in
a contagious world,

I think we'll see fewer
advertisements and more

interpersonal communication,
less money spent on how can we

interrupt consumers
from their television

show or their
favorite radio program

and shove an ad in their face,
so they'll pay attention to us.

And more, well, how can
we get their friends

to tell them about this product?

I think if you're
a small company,

this book is great news.

You might have thought that you
need a celebrity to talk about,

or you need some big blogger
to tweet about your restaurant

or it's not going
to become popular.

What this book
shows is how anyone

can apply these principles
to help their idea catch on.

If you're a big company, I think
you need to change direction

a little bit.

You need to stop focusing
on finding special people

and think more about how to
create content that's going

to be more likely to be shared.