Two of the biggest "mass market" brands are using QR Codes in their advertising. ASDA - the UK arm of Walmart - and Martina Cole - one of the UK's best selling authors.
Here's a close up of the code
It's a reasonable physical size and the information density isn't particularly high - so well done on that front.
I'd place a bit more whitespace around the code - but it scanned easily enough on my phone.
The website itself is ok. Nothing stunning.
It's a great concept site - like Post Secret or GroupHug - but it really ought to be more mobile friendly.
The URL isn't specific to the code - it's just http://www.thefamilysecrets.co.uk/ - so they have no real way of knowing how many people scanned it.
Still - good to see QR codes becoming more prominent.