$1.1bn is a lot of money. The kind of money entrepreneurs lay in bed and dream their start-ups could be worth. But seven years on from David Karp's first thought of Tumblr, it's grown immeasurably in potential and has been sold to Yahoo for $1.1bn. We take a look at how it all started, and how Tumblr became worth more than the GDP of several small countries.

It costs less than you might think to start your own business. The average cost of starting-up is £312. That's less than a new iPad, a third of the price of an arsenal season ticket and, most importantly, less than what the average employee earns in just one week at work.

Running your own business brings freedom, flexibilty and the privilege of making your own decisions about well, everything. But with great power comes great responsibility and with that comes pressure.  Dealing with pressure effectively is essential to running a successful business. With that in mind we persuaded Michael Neill, bestselling author of The Inside-Out Revolution to give us a guest blog about pressure with a few tips on how you can use it to your advantage.

This week's #O2SmartaBiz competition was the biggest yet! O2 and Smarta are thrilled to present the winner, Footfall123. Pushing forward great technology is always worth celebrating. Footfall123 are doing that spectacularly with the new Time Out Card, launched last week with the business' redemptive technology. Founder, Ben Chesser, stopped by to tell us what makes Footfall123 smart. Has your business been smart this week? Let us know by tweeting us using the #O2SmartaBiz hashtag and you could be a winner too!

On the final day of the Premiership season, there'll be more than football for the camera's to focus on thanks to a brilliant charity event from Mask-arade. The mask company have organised for 4,000 replicas of the face of Aston Villa's Stan Petrov, who suffers from leukaemia, to be placed on each away seat for their match at Wigan to raise awareness for Cure Leukaemia.

Co-founder of the Smarta 100 winning company, Chris O'Nyan, told us why his company has always helped charities, and why other small businesses should too.

Combining design and investment opportunity in a real estate management company was Nivin El-Gamal's idea on how to offer a unique property service. Check out the Galaxy Stars start up in 60 seconds here.

The Prime Minister has called for British start-ups to pitch to him at this year's Conservative Party Start-Up Hub. The 12 best businesses will then showcase their work in front of thousands at the Conservative Party Conference. The four day event will give these start-ups the chance to demonstrate their ideas to some of the most influential figures in British Business. We spoke to Competition chair, Damian Collins MP, about what it will take to win and why start-ups should enter.

Former The Apprentice candidate and founder of Cult Wines Tom Gearing shares his take on Lord Sugar's decision in episode three of this series.

I've seen loads of businesses making smarter choices when it comes to their cashflow lately, but there's still more they could do to protect themselves against hitting hard times. Luckily, the King is here with another tip to shore up your defences and leave your business feeling secure. But this one's not just for you, it involves your trusty team mates too.

When launching any business you have to be prepared for ongoing change and never stop looking for ways to improve. Peter Clayton, founder of Tradeplumbing.co.uk, explains how being kept on his toes in a competitive online market is good for his business.