HOW would you like a brand new TV for $10?

The latest twice-yearly Click Frenzy online shopping event kicks off at 7pm AEDT tonight, featuring 4000 deals from more than 500 Australian retailers, with discounts of up to 99 per cent available to subscribers.

"We're doing ridiculous prices on things like Google Home for $2, an Xbox for $4, we've got an LG 55-inch TV selling for $10, we've got a FitBit going for $2, a 10.5-inch iPad Pro 64GB for $10," said Click Frenzy founder Grant Arnott.

"Those run out very quickly. It varies but they do sell out sometimes in 10 minutes. They're part of our subscriber-only treasure hunt. The way it works, we send clues out to subscribers via email, then a pop-up banner will appear and they'll get a promo code."

The chances of scoring one of the massive discounts is slim - or in the words of one Facebook commenter, like "winning a race against Usain Bolt". Last year's sale sparked outcry from some shoppers who were left empty-handed, after deals sold out within seconds and attempts to order items returned an error message from the vendor.

Mr Arnott would not reveal the exact number of 99 per cent off deals, which are funded by Click Frenzy out of its marketing budget, but said many retailers were offering up to 70-80 per cent off.

"I'm really impressed with the overall quality of the deals," he said.

"Every year it continues to grow in importance, and retailers are getting really serious about how they execute. There's only a small selection of these 99 per cent off deals but the majority of customers are coming because of the 80 per cent discounts on fashion, cosmetics, homewares. People are coming to shop for deals with their favourite retail brands."

There will also be large travel discounts available, with brands including Webjet, Flight Centre, Air New Zealand and TravelOnline taking part. Other participating retailers include Myer, Chemist Warehouse, Cotton On, eBay, Rebel, Peter Alexander, Sony, Microsoft, Adidas, 2XU and First Choice Liquor.

Around two million Australians are expected to descend on the Click Frenzy website tonight, about half a million more than last year. The 24-hour event generated about $200 million in sales last year, and Mr Arnott said he was hoping for $250 million this year.

Mr Arnott said he was confident the site would be able to handle the traffic. "We still hear a lot about the site crash, which was our first ever event in 2012," he said. "We haven't actually had a crash since. It gets a bit overblown. We run on Amazon Web Services, the best hosting infrastructure you can have, so we're very confident we can sustain the volume."

He said with all the focus on online shopping events such as Singles Day in China and Black Friday in the US, it was important to have an event which contributed back to the Australian economy. "All that does is send people to overseas retailers," he said. "We find Australians favour Australian retail brands."

Meanwhile, online retailer last night kicked off its competing event dubbed Kogan Frenzy, with discounts of between 10-25 per cent on items including the iPhone 8 64GB, Samsung Galaxy S8 64GB and 55-inch 4K LED TV. Kogan is also offering a $4.90 mobile deal offering new customers 16GB of data for 30 days.

"We're very excited about Kogan Frenzy," Kogan founder Ruslan Kogan said. "It starts earlier. It runs for longer ... This year we have over $50 million of the most popular products in stock and we're expecting Kogan Frenzy to be the biggest frenzy ever."

According to comparison website, more and more Aussies are becoming interested in flash sales like Click Frenzy, with research showing an increase of 67 per cent in interest between the May 2017 and November 2016 events.

But Finder money expert Bessie Hassan said while it was easy to feel the pressure, it was a good idea to think before you click. "It pays to do a quick online search to make sure you're getting the best deal," she said.

"The same item may be cheaper at another retailer that isn't taking part in this particular shopping event. If you miss out on a few purchases, bear in mind that Black Friday and Cyber Monday are just around the corner."

Retail expert Brian Walker from the Retail Doctor Group said there would likely be good deals around technology and mobile phones, but also warned against purchasing on impulse. "Research, research and then research some more," he said.

"There is so much activity, [but] much of it is clearance stock, distressed stock, that one just has to be price shopping, comparison shopping. There are so many aggregate websites now to compare offers, it really is all around research."