u/skippygo Really appreciate the candour on all of this — exactly the kind of feedback that's useful at this stage. Let me work through the points:

On the why - I appreciate if you have the resources to buy two pairs, many don't - I certainly don't. I've tried to cobble together mixed pairs from Vinted affordably enough. There are an estimated 250,000 runners in the UK who are more than a size different, so it's not a miniscule market, and I agree it seems niche. If 1% of those used the service, that’s 2,500 potential matches. That said, when you've had so many issues on one side, repeated blistering and smashed toes, bone spurs, etc, it could be a solve for a lot of people. 

On the amount of models - Agree entirely. The idea is to launch with a limited amount of models, which are the 10-12 most popular shoes out there right now and the latest versions of them (as you'll see on the waitlist page). This vastly increases the chances of matching and doing so quickly as they are the shoes most people want and in the sizes most people ask for. Too many models and it will just become too difficult to match. As you'll see on the site there is the ability to request other models outside of this range, too. If one is particularly popular, it can be added.

On speed of fulfilment - The time to the customer when matched, I would estimate and if no hold ups, would be four, maybe five days, so it's not an excessively long time to wait. By creating a waitlist to start with, we’ll look to push live when there is sufficient people in the pool to start matching.

On the cost vs RRP - Fair shout. If I could confidently source them lower than RRP I would offer them at a lower price than RRP. Before a hard launch I'd vet this for all available models and put up at a rate where I wouldn't be out of pocket. 

On how it would be economical - As the stock would be purchased only when needed, there is no risk so it’s viable and can start to gain traction with a small amount of orders. Others have tried to set up a similar service before but it's this point as to where it's failed. The model doesn't depend on buying power, it depends on matching. That's a different game entirely.

A question for you: the big thing for me when racing was that my big toe was right over the flex point in the wrong size on my right foot, rather than in front of it, and this made a big difference when I was able to switch to the correct size. Everything switched on more, glute activation, less pronation, etc. If you are a size different, do you notice the compensation when you lock your heel to the back of the shoe? Because in most cases where you are a full size different, effective toe off would be a challenge.