We have customers of all "maintenance" levels.
Some will register hundreds of domains and we'll never hear from them.
Some will register one domain and will have problems just entering their phone number - not to mention configuring nameservers or making changes to their information after the fact.
We hear from customers regularly who don't understand that they need to actually have working nameservers somewhere in order for their "website to work." And will come back to us to find out why their home page no longer displays. Always a problem with their web host - but they ask us because their hosting company doesn't answer them.
We get lost password requests every day - even though customers can request their password be emailed to them right from the login screen.
Our largest support costs however are associated with domain transfers. We agressively solicit transfer business, however we lose money on 50% of these due to the incredible hassles that transfers can be. Fortunately the Transfer Task Force is hot on the case, and we expect the failures and "hoop jumping" to be eliminated over time. Most of these customers appreciate the efforts we have gone through to "save them from Verisign" or whomever they are transferring away from - and they continue to register new domains with us, or consolidate all their domains - so eventually these customers generate profit.
If you plan to have 1 hour resolution to customer problems, this is not a one man business - that's for sure. It's also a 7x24 business, as customers will come from all over the world. We recently had a rush from Germany for some reason, with almost 40% of our business for two weeks coming from that country. We have not followed up with these customers (a large number of unique customers - not just a couple large ISPs) to find out how they all found us, but we will. We also have a considerable number of customers in Japan and Austrailia.
myOstrich Internet - OpenSRS Domain Names & Digital Certificates