We used to get an organic veg box delivered, but had to give it up, as it was just costing way too much (£15/week for a small ish mixed box of fruit & veg).
The produce was always fresh, and tasted great. However, the main problem we found was that there were enough carrots or mushrooms say for one meal, but we eat both more than once per week, so it meant we had to buy extra from the supermarket anyway (no greengrocer nearby unfortunately). Then you had the usual 'mystery veg', which was fun for a while, but you ended up scouring the net for recipes involving celeriac etc!
So, some feedback:
1) I would definitely subscribe to a weekly or fortnightly veg box. Personally I would pay a premium for fresh and local, but don't like feeling ripped off for organic (part of my job involves fungicide manufacture, so buying organic feels a bit ironic in my case!).
2) If you're including 'wierd' veggies, including a recipe card, or having suggestions on your website would be a great idea. <blush> I remember once having to phone my mum to find out what something was, before I could work out how to cook it!

</blush>
3) In our case, it was important to be able to pay online, or to leave a cheque in the shed, as there's not always someone home during the day.
4) We rather liked getting wierd shaped veggies, or veggies covered in earth. It may sound stupid, but somehow it added to the taste - meant you felt you were eating 'real' food!
5) Cost is important. We were happy to pay a bit more for organic etc, but not as much as the premium we were being charged (same goes for supermarkets etc).
6) Could consider also selling yoghurts / eggs etc. All adds to the service.
Hope that's helpful!!
Womble.