How To Win In The Den casts an analytical eye over the highs and lows experienced by the hundreds of brave entrepreneurs who have dared to enter the Den over the last nine series, packed with tips and advice so that even the least entrepreneurial amongst us can benefit from the advice.

This week, the Dragons share their thoughts about how the strength of an idea is the key to unlocking their cash in the Den.

Back in 2007, eccentric inventor Mark Champkins was looking for investment in his range of school products and ended up giving Peter Jones 40 percent of all his future ideas. But has the entrepreneur delivered on the Dragon's investment?

Cousins Lisa Marshall and Shelene Mitchell were two of the most unlikely entrepreneurs the Den has seen, but they surprised the Dragons with a water-tight patent for their stackable outdoor plant container. Deborah Meaden finds out how the likable pair are doing a year on without a Dragon's investment.

And when Hairdresser Shaun Pulfrey demonstrated his hair-detangling brush, the Dragons were unimpressed and declined to invest, but little did anyone know that Shaun's idea would go on to become a global brand. Five years on, just how successful has Shaun really become? Plus, we catch up with traffic enthusiast Derek Cousins whose idea to put flashing lights on street signs is a strong contender for one of the worst the Den has ever seen. The Dragons advised him to give up, but did Derek listen? Show less