Wow, love the idea and feel of the site ... as others point out it's the 'quirky' style that brings the car boot feeling. That said, I have to be blunt mate, you need to sort out a lot of issues.
One of my biggest gripes is the main navigation. It looks so simple to use, until you try to and on desktop a simple example is try using a mouse to get to Sell > Book a Stall ... 9/10 times my mouse moves off and the nav disappears before I get there. I need to hover Sell, move down to Previous & Active Stalls and then straight left to get to Book a Stall. The other thing I would also expect is that clicking 'Sell' would take me to the main sell page about setting up a stall etc and the 'Buy' link would take me to 'Go Booting' as that's why I'm here, or better a page of all items for Sale, or a list of Stalls with items for sale. Also my final gripe on the nav is so many items on the navigation under sell or user require you be logged in. Would be much clearer if both had an overview of the services offered by having an account such as what 'Stats and Points' are, and hide the other options unless they are logged in. Wishlist should also be a constant like a shopping cart, even when empty it shows the service is there and not hidden in a sub navigation.
Second you need to sort out the stalls (pages). I like the idea of the 'Go Booting' page being a list of stalls but I would suggest a carousel of the stalls products with auto play or bigger left and right arrows to show there's more and hide them if there are only 2 products as no scroll required, something like Slick would work. My biggest headache was once I realised I could scroll left and right I expected them all to scroll, but then some perfectly match to the edges so I can't tell if there are more products or less, really confusing. Also I would suggest a link to 'view stall' which would be a page of all items from the seller and any 'filters' applied on Go Booting should really grid the products and not separate still by stalls. By adding stall pages you could potentially generate social links etc made by the stall holders etc. Oh, and on a side note the term 'aisles' baffled me, is it instead of 'pages'?
Finally design wise please, please, please stop using the full width of the browser for the content and wrap the content with a max-width! It turns paragraphs into 24" wide sentences, a real pain to focus and read the content.
Cheers. Aw, I like the animation ;-) I was told it was good for seo. You think it would be better to have a few fewatured items for sale on there instead?
The principal behind animations being 'good for seo' is for deeper indexing of lower tier pages such as products or categories. That said it's no better than a humble link. The animation coverage on the home page is taking up prime real estate which would be much better served explaining what the site is for and for getting people straight into the buy, sell or register pages.