I bought a voucher for some home delivered fruit and veg from our deal (I think). I redeemed mine at the first opportunity. Subsequent to that, I have received emails either from or on behalf of the merchant alerting all buyers to the fact that there is plenty of availability this week or a similar message.
If the group buying companies and the merchants were serious about actually servicing the vouchers, they would have an opt in system where buyers could receive periodic messages about availability, especially during non peak times. I have perhaps 40 meal vouchers outstanding with various companies. I would opt in for all of them. It would serve as a reminder for purchasers to use their vouchers and would probably shift some of the demand to earlier and non peak periods within the vouchers time frame.
A win-win scenario, providing the the various parties actually want the vouchers to be redeemed.
I agree, such a system would be great!
Sadly, though, I don't think they actually want you to redeem your coupon…more money in their pocket!