Until recently the answers ranged from traditional matchmaking

to meeting a partner at work. But now for many, that search starts online.

When you're using a dating app, you have to be really open-minded.

You can have extremely incredible dates and you can have dates

where you're like: "I definitely wasn't feeling that."

So what does all this online romance mean for us in the real world?

People have been looking for love online for more than two decades,

with the website Match.com launching in 1995 and the gay dating app Grindr launching in 2009.

But advertising for a partner goes all the way back

to the 17th century, shortly after  the advent of the newspaper,

when bachelors ran personal ads looking for a suitable companion.

It's believed the first woman  ran a newspaper ad in 1727,

stating she was “seeking someone nice to spend her life with".

Lonely soldiers during the First World War advertised for pen pals.

And in the 1960s technology got involved. Operation Match, was a computer dating service

invented by Harvard undergraduates in 1965 that paired people up based on a questionnaire.

That all changed in 2012,  when Tinder invented the swipe.

People swipe right when they like the look of someone,

or left if they're not so sure.

When two people like each other, it's a match and they can then start messaging.

Another popular dating app, which allows women to make the first move, followed,

when ex-Tinder employee Whitney Wolfe Herd launched Bumble in 2014.

Its parent company, dating group Magic Lab, is now worth $3 billion.

The online dating sector as a whole is projected to become a $9 billion industry by 2025.

So how have these dating apps and websites changed the ways we look for love?

I'm here to meet anthropologist Anna Machin to find out.

It's a different set of criteria that make up that mate value.

The big sort of overall way we fall in love  hasn't changed that much to be honest

because obviously it's evolutionarily ancient. So the actual neurochemistry that goes on,

the things that we find attractive hasn't changed.

But what dating apps have done is they've in a way changed the way we search.

When you get a connection, when you get a match,

you get a dopamine hit,  you feel good about yourself.

Somebody likes me, that's great, and dopamine is addictive.

Users splurged more than $2.2 billion on dating apps in 2019,

with Chinese app Tantan seeing the fastest growth.

But it's Tinder that leads the way for overall spend,

with its upgrade and subscription options generating the most income.

Users parted with so much money within the app in the past decade,

that it came second only to it Netflix  in terms of consumer spend.

But does all of that money mean people are finding their soulmate?

Well according to a 2016 study, more than a third of men on Tinder

swipe right on every image they see.

We're seeing these very extreme behaviors of men fancying everybody

and women being very, very picky  about who they then actually try and like

because otherwise it's just not working for them.

Match Group, which owns Tinder, Match.com and OkCupid,

is the biggest player in the online dating space.

The company, which is listed on Nasdaq, made revenues of more than $2 billion in 2019.

More niche apps are also springing up, focused on sexual orientation, religion,

preference for facial hair  or people living in rural areas.

And there's Lumen, a new dating app for people over 50,

which is owned by MagicLab, the parent company of Bumble.

We'd realised there was a growing number of over 50s

who had seen that there were dating sites

supposedly designed for them, found them quite old-fashioned,

wanted to be using dating apps, but then most of the dating apps

that were out there were designed for millennials.

We knew there were men in their 50s and 60s who want to date women the same age as them

so we decided to create a place where you know that everyone on the app is over 50.

While apps have certainly had an impact on dating,

they've also been blamed for encouraging a so-called hookup culture

and some people aren't so sure about them.

I think the swiping feels like quite depressing so it's like every time you swipe through

it's like you're looking for a better person, it's almost like there's too many people there.

Males are always dominant on the app

and they kind of keep on swiping and get less matches,

however females are like getting a lot of matches,

they have to filter through a lot of stuff.

I get messages from people that are completely different

to anything somebody would say in real life.

Knowing that I feel like I can go home and swipe and find someone else,

you equally know that the other person can do that too.

I feel like it's the same people on all of them,

they are just different user experiences.

My hope is that I'll just  meet someone in real life.

If you're looking for something long- term, Charly Lester has this advice.

One of the key things with the dating is making sure you're in the right headspace to be using a dating app.

If you're not feeling particularly confident in yourself,

then being rejected potentially by complete strangers

can actually have a real effect on you.

I speak to a lot of people who, the way they talk about dating,

it just feels quite arduous and like it's become really this night time job

that they feel they have to do every night and it shouldn't feel like that.

If you don't have enough time to be dating

then you probably don't have enough time for a relationship.

As dating apps are relatively new, academics are only just starting

to understand people's behavior on them.

And there's a whole lot of new terminology to describe what they're up to.

Ghosting refers to someone who breaks off all communication and contact with no warning,

while breadcrumbing is when a potential date sends endless messages,

but never wants to meet up, a bit like a pen pal.

There are some people who use dating apps  who aren't necessarily there to find a match

but they are competitively seeing how many matches they get.

They're called collectors

and they are simply there to boost their own self-esteem maybe

by getting however many matches a day.

There's another new term that has come out called 'obliga-swiping,'

which is you swipe, and then you tell yourself you are doing something to find a partner,

but actually you never ever take it any further.

But among the new swiping apps, there's still a place for the more traditional matching technique.

Dating website eHarmony uses a detailed questionnaire.

We basically then match you according to these 32 dimensions,

basically deep personality and value traits that we think are really important.

We are getting to the tipping point very soon where the majority of people will meet online.

I think we predicted around 2035 it will be the case.

What's been the impact of the new apps on eHarmony?

They have brought into the category a whole bunch of new users that wouldn't

have necessarily thought about doing online dating in the past.

Over time and as maybe a bit of swiping fatigue starts to appear

and these people's need change and they start looking

for something a bit different, very often we see them coming to eHarmony.

So what will technology mean for dating in the future?

Will we ever go back to meeting people in real life?

This neurochemistry of attraction isn't released when you are looking at an image online,

when you're texting, when you're WhatsApping,

all these things, you're not getting that.

People are starting to go back to what they call old fashioned dating.

Because they are realizing that actually,

all that swiping, particularly if you are a woman,

doesn't necessarily end up with a pool of men that are necessarily right for you.

Because they are so visual, they are much more male friendly than they are female friendly

and I think we might start to see apps which really do encourage a cut down on the endless remote texting.

Thanks for watching. Are you a collector or have you been guilty of bread crumbing?

Let us know in the comments below. And don't forget to subscribe.