BBC News Published image captionOne in five of us is likely to experience some sort of disability in our lifetime Increasingly for businesses, factoring in the needs of disabled customers from the start is becoming a crucial part of product development. Yet this huge market - the so-called "Purple pound" - remains largely untapped as many firms are failing to successfully adapt for customers with disabilities. The purple pound refers to the spending power of disabled households and is now worth some £274bn a year to UK businesses, according to the advocacy group Purple. As one in five of us is likely to experience some sort of disability in our lifetime - how can firms successfully access the purple pound market and improve their bottom line?