In October 2008, I was days away from confirming a €2 million sale for my first tech startup ukdata.com. Then the banking crisis hit. In the years that followed I went on to set up the popular ecommerce site Simply Moleskine and Company Check, the business information site now used by more than three million unique visitors per month - both achievements only made possible by that first close-call.

Ideally, as an entrepreneur you would only set up one, really successful business. But it’s rare that anyone gets it right first time around. For most of us it takes a few goes before  getting to the one that will make the serious money.

I never planned to become a serial entrepreneur, it just happened by accident. By the time I was 40 I’d set up three businesses and you could say I was chasing the dragon each time - with each one there was a different plan, a different opportunity and different motivators for doing so.

The first one, ukdata.com was launched in 2000 to commoditise and simplify access to credit reports for businesses at a time when nobody else was doing it.

We felt our way through the entrepreneurial jungle that first time and after a successful few years we received a buyout offer worth £1.2 million, which we turned down. Our reasoning was: ‘after we split this and pay Capital Gains Tax (no entrepreneur relief in those days) that’s eight years’ worth of income which we felt didn’t reflect the value. We might as well carry on growing it and then sell for a higher price’.

"Everyone wants their business to be worth as much as possible, many fall into the trap of overvaluing it"

We were then offered €2 million (£1.5 million) for it just days before the banking crisis hit in 2008. Then the stock market crashed, Gordon Brown had to rescue the banks and the deal quickly fell through.

It doesn’t take a genius to work out the moral of the story, however I’ve always been philosophical about the whole episode. Mainly because it taught me the single hardest lesson any entrepreneur can learn; the importance of letting go.

The qualities that set entrepreneurs apart from the rest - an eye for an opportunity, unfailing confidence and above all, dogged determination - are the same ones that can blind them to the reality that they’re operating in.

Everyone wants their business to be worth as much as possible, but because it’s ‘their baby’ and they can’t let go, many fall into the trap of overvaluing it. It’s like owning a house; people always think their home is worth more than it really is because to them it’s emotional. In reality though it’s only worth what someone else is willing to pay.

In my case I’d built my first business up from nothing. I’d put so much into it and because of that, I didn’t let go at the right time. The question that I should have asked myself, and the one that future entrepreneurs need to ask themselves is: ‘is it realistic that you’re going to grow this one into some enormous thing? Do you have the time and the ability to do it? Or should you accept an offer that secures part of your future and allows you to go off and invest in more businesses?’

Knowing when to leave something if it’s not working out is as important as knowing when to make the jump into entrepreneurship in the first place. This is especially relevant for young entrepreneurs with time on their side.

After that first deal fell through I saw I had two choices; give up and go and get a real job or dust myself down and carry on. With hindsight, it was never a real choice.

The digital marketplace carried on changing apace and so I changed with it, first with Simply Moleskine - using my knowledge of ecommerce to tap into a moment of popularity and build the biggest website selling moleskine notebooks in just 18 months.

Then Company Check set up in 2011, which I grew into one of the UK’s most visited sites, with more than 500,000 registered users signed up to date.

Both examples have proved to me the second most important lesson any entrepreneur can learn, that with every failure your chances of success increase significantly.

It takes a special kind of personality to adapt when circumstances change, but your chances of success and, ultimately, a bigger sale, improve with every business you set up - mainly because you won’t be making the same mistakes twice.

The techniques I’ve used to build my businesses has got more sophisticated as I’ve matured as an entrepreneur. It’s still hard work, but it gets easier the second or third time around because there’s less of a huge leap and you already have the contacts and relationships in place.

You can get more from your suppliers and customers - they take you more seriously and there’s no question in their mind about whether or not you can do it.

You can get a bank account sorted out in a day rather than a few weeks; you wont have as much trouble getting a business plan approved; you won’t struggle to line up credit card processing facilities and so on. You’ve got proof that you can survive and pay the bills.

If you set up just one business there’s a danger of getting caught in a small ecosystem, but with multiple businesses you tend to get out more and often meet more interesting people. So your network grows and it gets easier to do all sorts of things.

In my case, when one didn't work I did it again and again until I achieved my version of success. It doesn’t matter what ‘success’ looks like to you, it could be money, flexibility, time off, whatever. If one doesn’t work out you can always do it again.