Speaking to iTnews, ispOne director Zac Swindells said growth of the offering among the sub-wholesaler's 150-odd ISP partners was already above expectations.
"Subscriptions are running at about 20 per cent of what the monthly fixed broadband number is," Swindells said.
Optus was recently forced to upgrade backhaul to its base stations to reduce congestion on its 3G network.
The decision was due in part to higher-than-expected growth in the Virgin mobile broadband offering, which rapidly increased subscriber numbers.
Swindells said he was confident that Optus had learned its lessons and would be more proactive in keeping network investments in line with new subscriber growth.
He cited an example in Wagga Wagga, one of the regional centres selected to test the mobile broadband product offering.
"The ISP Country Energy had an issue where they didn't expect the level of penetration they achieved," Swindells said.
"Within four days of reporting the capacity issue, the problem was resolved. The fact it happened in a regional area gives us confidence it will happen in a metro area as well. It's a very important product for Optus."
Swindells said the product enabled ispOne's partners, particularly those in regional areas, to offer a branded mobile broadband service that could compete with the likes of Telstra Next G.
"It's a cost plus margin product, it's easy to provision, bill and service and it's fully brandable," he said.
"We also offer it as either a layer two or layer three product so partners can value-add business grade services around it."
Swindells said ispOne would also proactively monitor usage to help its partners prevent the phenomenon of bill shock impacting their customers.
Swindells said the decision to resell Optus pre-dated the naming of the service as ‘metro-comparable' under the Australian Broadband Guarantee scheme, but he said the development would potentially help regional ISPs make more sales.
ispOne continues to offer fixed-line ADSL2+ wholesale services from an earlier agreement with Telstra.