[I] In 2007, design graduates, Joe Gebbia and Brian Chesky were struggling to pay the rent for their San Francisco apartment. [II] Hearing that a conference was coming to town with no available hotel rooms, they created the website airbed and breakfast.com, advertising three airbeds in their home at $80 each a night, breakfast included. [III] Within six days, they had three guests sleeping on their floor, realizing this was the start of something big. [IV]
Being budding entrepreneurs, they decided to take their idea further. They enlisted Gebbia's former flatmate, Nathan Blecharczyk, a computer science graduate, to help develop the website. Their aim was to target conferences and festivals across the USA, getting locals to list their rooms and travellers to book them. The new website was launched just in time for the 2008 Democratic National Convention in Denver, where Barack Obama was set to speak in front of 80,000 attendees. Within a week, they had 800 listings, which, while impressive, did not resolve their financial issues since the site was not yet profitable.
To address this, the team began to manage payment for bookings, charging three percent to hosts and between six and twelve percent to travellers based on booking prices. As interest from investors grew, they moved the company from their flat to a new office and hired additional staff by April 2009, when larger investments began to flow in.
Since then, Airbnb has flourished, now boasting over 1.5 million listings in 34,000 cities across 190 countries, and is rumored to be valued at around $20 billion.

A secret job in the retail trade
[I] I am in a supermarket, doing my best to look like any other shopper browsing the shelves. [II] My mission on this trip is to buy something I fancy from the bakery, which means I'll have to interact with the person at the counter. [III] I'm hoping to pass off the handwritten notes I'm carrying as a shopping list, because no one must know why I am here. I have to keep my identity secret because I am a mystery shopper. [IV]
My job involves visiting five to ten different stores a day and scoring them on, among other things, their appearance and cleanliness. With the €20 I am given to spend at each store, I purchase the obligatory item that enables me to assess the service I receive at the checkout. Adding the value of my purchase to the €225 I make in a typical day of eight hours of visits and two hours filing reports, I earn more than enough to live on.
However, assignments paying as well as mine are becoming few and far between due to the soaring demand in my line of work. Retailers increasingly need to maintain standards so as to offer consumers a quality shopping experience and keep them from turning to the internet. However, to date, there are more than half a million mystery shoppers registered in the UK, making competition for jobs very fierce. Today it isn't only other shoppers I hide my identity from; even my friends and family don't know who I work for.

[I] For years, the River Thames was a health hazard because of pollution, and in 1957 it was declared biologically dead. [II] Half a century later, the Thames has won international prizes for rivers that have been restored. [III] There are now hundreds of different types of animal and bird feeding on its banks, over 125 different species of fish swimming beneath its surface, and even seals and dolphins have swum up the river from the coast to visit the centre of the city. [IV]
Since the beginning of the Industrial Revolution, Londoners had become used to suffering from coughs and chest infections caused by smog, which is a combination of smoke and fog. However, when the smog of December 1952 caused four thousand deaths in one week, the government finally realised that something had to be done. A series of 'clean-air' laws were passed to avoid a repeat of the tragedy, and since then the quality of London's air has improved greatly, although there is still plenty of work to do.
At the beginning of the new millennium, because of the number of vehicles, traffic in London was moving at the same speed that it had moved at a hundred years before, when people travelled in horse-drawn carriages: just 16 km/h. To improve journey times and the quality of London's air, a daily charge of £5 was introduced in 2003 for all vehicles being driven in the city. Not only did the number of cars on the roads immediately drop by 15%, but also the number of people cycling increased by 49%, so people benefitted from cleaner air and more exercise. In the last decade, the number of vehicles in central London has fallen by a further 30% and plans to reduce the number of parking spaces for cars will probably cause it to drop again.