I reckon split testing that style of ad copy with something more like:
"Don't miss the online property boom - secure your premium domain real estate before it's too late!"
I'm not saying it would perform better, but it would be worth testing given that fear motivates more than opportunity.
Then I'd be directing them to a more specific landing page than the NetFleet homepage.
I'm not knocking the NetFleet homepage, I think it's great, but it is a bit busy and if you are new to investing in domains you are going to head off in all different directions or worse, get overwhelmed and leave.
I see NF's two initial objectives for people entering the site via braod advertising is, one, educate visitors on the value of domains, and two, get them to register so you have their name and email address.
So I think the landing page needs to be a lot more informational (explaining the value of domains now and in the future - maybe with a video or two) and if it's goign to show prices of domains at all it probably needs to promote the NF catalogue domains more because it will make more sense to potential new investors to see a listed price for a domain because I don't think many people are going to click an ad on Realestate.com.au that intrigued them and then all of a sudden be confident enough to start bidding at the NetFleet auction straight away nor are they going to be thinking domains are valuable enough to invest in if they just see a list random domain names which have current bids of $10 on that day's auction.
So I'd keep the page pretty simple and probably select 15 to 25 reasonably priced catalogue domains that are in the $500 to $15,000 range to give them an idea of asking prices and the sorts of things that are available and then say there are X,XXX domains for sale along with a search box and then I'd probably have the current top 10 domains at today's auction below that along with the count down timer.
Even then I think the bounce rate will probably be quite large, so maybe you could create some sort of "domain investors guide" at the top of the page for people to download when they give you their names and email addresses so you can contact them in the future whilst at the same time give them some informational resources so they can start to get more informed about domain investing which will build their confidence to the point where they might be willing to start investing in domains...
Anyway, just food for thought.