Under the new NBN pricing plan, service providers will be rewarded with reduced wholesale charges, provided they increase the average amount of data capacity they provide to their customers.

The model, to take effect from Thursday, is in direct response to Australia's surging data usage.

Last year the nation downloaded a record 2.5 billion gigabytes of data. NBN-connected homes are downloading 1.2 times the national fixed-line average.

Since the NBN announced the new pricing model three months ago, retailers have increased the average amount of wholesale bandwidth purchased by 11 per cent.

"The discount is absolutely for the retailers but it allows for retailers to control their costs more and provide a greater range of plans for consumers," Sarah Palmer, NBN's executive general manager for product and pricing, said.

"We will calculate the discount based on usage from the month before...if retailers choose to pass on their discount to consumers, they can. But regardless, the more capacity they buy, the better the experience for consumers."

Telstra, however, said NBN had moved in the right direction in lowering wholesale prices, but that the move would not be positive for all consumers.

"The pricing structure means service providers with more low use and voice-only customers will pay a higher price to NBN for all their customers... This gives providers a disincentive to provide services to customers who only use small amounts of data or have voice-only plans," Telstra spokesman Steve Carey said.

The pricing plan comes as the latest Akamai State of the Internet Report (Q1 2017) revealed Australia's internet connection speed was now ranked 50th in the world, just up from 51st in the same report last quarter.

Ahead of Australia are the usual suspects in South Korea (1), Switzerland (5) and the US (10), as well as Thailand (21), Ukraine (39) and Kenya (43).

According to Akamai, Australia's average speed is up from 10.1 Mbps last quarter to 11.1 Mbps this quarter.

Comparatively, the average connection speed in Britain is 16.9 Mbps and in the US, 18.7.

But to Australians disappointed by the result, Akamai's Asia-Pacific spokesman Vincent Low recommended a "little patience".

"Australians are some of the highest users of the internet...from last year to this year, even a single digit growth is relatively high," he said.

"People are using higher quality content, live media broadcasting on different platforms. In the next few years I think it's going to pop."

He said Australians should not read into its ranking falling behind nations such as Kenya, which "doesn't have nearly as many devices" or equivalent broadband penetration.

Mr Lowe added that Australia's average mobile connection speed of 15.7 Mbps, which leads the Asia-Pacific, was a positive outcome of ongoing investment in the wireless mobile network.

An NBN spokesman said the Akamai report did not provide a full picture of Australia, because it surveyed millions of people who were not yet connected to the network.

"...There may be countries which have reported higher average speeds???[but] some countries do not have extensive broadband networks," he said.

"The average broadband ranking recorded by Akamai will only see a significant increase if Australians choose to purchase higher speed plans from their retailers on the NBN network."

A spokesman for the Department of Communications and the Arts said the Akamai results proved that the sooner the NBN was completed, the "better Australia will perform in global rankings".

"Given the majority of consumers in Australia are still using legacy ADSL connections, it's difficult to draw conclusions other than the gains being made are coming from the NBN rollout," he said.

"The speeds measured by Akamai are also influenced by the streaming bitrate at which video and other content is being delivered to Australian homes."

There are currently more than 2.2 million homes and businesses accessing the NBN. The roll-out is expected to be completed by 2020.

A recent Galaxy survey commissioned by comparison site iSelect found almost 40 per cent of NBN users did not know what speed tier they were currently on. However eight out of 10 connected households were satisfied with their speed.