Black Friday may be losing its appeal in Scotland, evolving instead into a more strung-out buying process in the run-up to Christmas, analysts have warned.

Shoppers pursuing the best deals are realising the best way to do this is online and over a longer period to track frequently changing prices, consumer group Which? said.

It has already warned shoppers to "do your research" to avoid falling foul to bogus promotions after a study revealed half of last year's deals were cheaper in the months before and after Black Friday.

Retailers across the UK have been reporting better-than-expected traffic and sales figures, amid reports that the websites of some leading high street retailers including New Look and River Island had been crashing.

John Rogers, chief executive of Sainsbury's Argos, told the BBC Radio 4 Today programme that between midnight and 1am on Friday the catalogue retailer saw "over 500,000 visits to the website, up 50% year on year".

Currys PC World reported its "highest ever" number of orders - with an increase of 40% on last year - while Carphone Warehouse said orders made on mobiles were up 480% compared to the same time last week.

John Lewis said it was taking five orders every second online and the busiest period so far had been between 8am and 8.30am as people shopped on their way into work.

It also saw a spike of sales made through mobile phones between 8am and 9am, with a 21% increase. It said there were no problems with its website so far.

Explaining the online move, Pete Moorey, head of campaigns at Which? said: "More and more people are now doing research online before they buy.

"Actually, a lot of people hate the busy crowds and stress, some don't like the constant Christmas music and others believe they will get better deals online."

He added that the only way people would be able to get the best deals was to use a price-tracker over a period of time - something that "we would never be able to know in a high street unless you are going to walk in with a spreadsheet".

He said research carried out last year showed the best deals were only for about 10 per cent of goods, adding "for a lot of products out there people would have been better to wait".

Some 14 million British shoppers were predicted to go on a £1.97 billion spending spree on Friday - setting a new record - with more than half spent on the internet.

Online spending on Black Friday was expected to reach £1 billion, up 16 per cent on last year, while it was anticipated that the majority who opt for the high street will spend a lower total of around £961 million.

It is expected that consumers will spend £5.8 billion over the four days culminating with the so-called Cyber Monday.

But the chaotic scenes witnessed two years ago where brawls broke out over cut-price televisions were not matched at the shops this year. Instead, just a handful of customers waited in line outside many superstores before calmly purchasing cut-price electrical goods.