A new website is offering you the chance of having your entire bill refunded, in what is an interesting spin on the cashback model.

In order to make buying stuff more exciting, Boom25 will reward every 25th shopper by giving them all the money back on their purchase. 

Here's everything you need to know.

[Read more:John Lewis offers £20 bung with new credit card]

An alternative to cashback

Cashback websites have become a regular part of online shopping for me and plenty of others. The idea is incredibly simple - you go to your cashback site of choice and search for the retailer you are planning to shop with.

Follow the tracked link over to that retailer, and any money you spend will be monitored, with you receiving a percentage of that spend back in the form of cashback.

I’ve been using TopCashback and Quidco for a good few years now, and have earned more than £650 doing so. That’s essentially free money, in return for buying things I was hoping to purchase anyway.

However, one new site is aiming to do things a little differently, with the potential to deliver some much more exciting returns than traditional cashback websites, though your luck will need to be in.

How Boom25 is different

Let’s be honest, the cashback you earn on a single purchase through cashback websites is generally not too exciting. A measly 1% of that new shirt from M&S isn’t a lot.

Boom25 is trying something different, offering shoppers the opportunity to enjoy not just a few pennies here and there but possibly an entire shop refunded. All you have to do is get the timing right; every 25th shopper who buys something online via Boom25 gets every penny of their purchase refunded.

That’s what happened to Nodreen Kiwanuka, who was lucky enough to get the full £282 she had spent on an iPad returned to her by Boom25.

The 29-year-old from Kent said it was the first time she’d ever used the site: “Traditional cashback sites have never been on my radar but when I heard Boom25 refunds the entire value of your purchase I thought I’d give it a go.

"I was surprised by how simple and straightforward it was; I didn’t have to commit to anything, just input my email to register and that’s it. I continued shopping as normal once I was redirected to the Currys PC World website.”

A few days later she was told she had won, with the money quickly credited to her PayPal account.

Nodreen said that for avid shoppers like her it “really is a no-brainer” to use the site, and that it “adds excitement to your everyday online purchases knowing you could win your money back”.

Where does the money come from?

When you shop via a tracked link on a cashback website, the site earns an affiliate fee. It’s that fee – or generally a slice of it – that is then returned to you in the form of cashback.

Boom25 works in exactly the same way, except that those affiliate fees are pooled, ensuring there is enough in the pot to pay for every 25th shopper to get their spending refunded.

There are currently 568 retailers to choose from on Boom25, which is a fair bit smaller than the big two cashback names, though there are plenty of recognisable names on there, from New Look and Very to Boots.

Membership of Boom25 is free, and while Quidco and TopCashback both offer free memberships too, there are paid for memberships (where the first £5 of cashback you earn in a year is retained by the site) on offer, also which come with additional benefits.

Slow and steady vs a big win

With a traditional cashback website, you can earn decent sums, but it will often take a while. Sure, there are big sums on offer if you switch your broadband or energy deal through the site, but if you haven’t done your research first you might end up with a stinker of a tariff, all for the sake of a few quid in cashback.

Boom25 is more of a gamble – if you happen to be one of the lucky ones, then you’ll get a more significant return, all in one go.

It certainly adds an element of excitement to your online shopping, if that’s what you’re after.

The fundamentals of using Boom25 are very similar to other cashback sites really – only spend what you were going to anyway, rather than pushing yourself in the hope of getting a bigger return.

In fact, this is perhaps a bigger danger with Boom25 than with the others, where the prospect of getting the entire spend refunded may tempt you into spending more than you can really afford.

You can also get more steady rewards with a cashback credit card