I know of a few registrars in the past that have allowed customers to taste large volumes of domains. However most stopped the practice because the liability of not deleting the domains correctly was huge.
Probably best illustrated by way of example:
So, you decide to taste say 1000 domain names. The moment these domains are registered the registry (AusRegistry) debits the full amount of $19,250 ($19.25 x 1000) from the registrar's account. Therefore the registrar must have these funds in the AusRegistry bank account, otherwise it will be blocked from registering and renewing any domains at all - not forgetting they have other traditional customers to service. There is a zero lock on the registrar's account with AusRegistry and there are no credit terms available, ALL registrars must pre-pay their accounts.
NB: Makes it difficult for registrars to extend credit to their own customers when they themselves don't enjoy this privilege.
Next, over the 3 day grace period you monitor traffic to decide which domains are worth keeping. Most .au tasters have had to manually check and make decisions with as much time to spare as possible, just so they can let the registrar know which domains to keep or delete safely.
The registrar must purge the domains within the 3 day grace period, otherwise they will not be refunded by AusRegistry. If you miss the cut off by 1 minute, then bad luck.
In summary, you can imagine the liability required for tasting and the relatively small returns for the registrar. If the domains are not deleted, a registrar could lose thousands, all in the effort to chase a few hundred dollars profit.
All this changes however, when you have reliable automated systems that manage everything from the registration, the tasting, the traffic analysis, and even the decision making relating to which domains to keep and which to delete. Under these circumstances it all becomes upside, and you can taste all the way down to the wire. And here lies the challenge.
Best Regards,
George Pongas