0% Interest purchase finance - Snap! Finance (bad credit included)

sleepyjones

Snap! Finance : 15 week interest free financing
I'm not sure if these guys are new-ish but I've never heard of them, and neither has this forum, apparently, based on the search results.
I was window shopping sofas (online) out of sheer boredom, more than an actual need for a new sofa, and came across a shop that offers 0% interest for 15 weeks on finance with no fees.  So I did a bit of digging.
I am in no way, whatsoever, an expert in credit files or how to best manage my finances but I think my credit is average, not great but not the worst either (I only got my first credit card last year).  So, I went ahead and applied just to see what the deal was and I was automatically offered a £1000 "line of credit".  Previously when I used the MSE eligibility checker for 0% credit cards I scored around 20%  so never bothered to apply so I wasn't really expecting this to accept me.
Now, the bad part ... it could just be my circumstances and my credit history isn't favourable so the APR I was offered is a bit ridiculous : 

Amount of credit : £925.00

Payment every four weeks : £108.52*

Interest Rate : 110.00%

Amount of interest : £811.23

Total amount repaid: £1,736.23

Term: 15 Months
* Please be aware that the payment above is your estimated payment and is for guidance only.
Actual payment may be higher or lower depending on your delivery date and first payment date.
(APR : 186% (I think)

This is a terrible deal, obviously, but the crux of this finance is that if you pay it back within 15 weeks you pay no interest and no fees. 
You can also repay the loan early (after the 15 weeks) to reduce your interest, but I didn't dig into the fees for that.
More info here : https://www.snapfinance.co.uk/hello15

I'm not posting this as a recommendation, just as an option that's available to those with, maybe, poorer credit and I certainly wouldn't recommend even looking at it unless you know you can pay it back within the 15 weeks and also read any replies below before diving in, just in case there's something I'm missing.