Online sales are booming. So much so that Black Friday has shifted from a high-street event to an online one, in the space of just two years, as retailers extended discounting over a week-long period rather than a single day. 

In 2015 e-commerce sales were up 11% year-on-year, equating to an approximate £114bn expenditure, the latest figures from the IMRG Capgemini e-Retail Sales Index show. 

The Christmas shopping period as a whole, defined as the eight weeks between 1st November and 26th December, saw £24.4bn spent online; a 12% annual increase, and a record for the Index. 
The greatest concentration of sales during the Christmas period (17%) took place during Black Friday week, commencing 22nd November. During what has become the biggest event in the retail calendar, online sales increased 62% on the previous week, with shoppers splashing out an estimated £4.3bn on discounted goods. This represents a significant increase on the 44% growth recorded during the same period in 2014, and 20% in 2013, before Black Friday existed in the UK.