The day local retailers have long been dreading is finally upon us, but the launch of Amazon's full scale retail assault on Australia is only one piece of the puzzle. Aussies can't sign up for the Amazon Prime customer VIP program until next year, meaning for now deliveries still take days rather than hours.

The online retail behemoth still remains tight-lipped as to exactly when its famed service will arrive in Australia and what it will deliver.

Australians are clearly keen to get onboard, with 43 per cent of people intending to shop on Amazon in the near future, according to market research group Honeycomb Strategy. Almost half of Australians under the age of 40 already prefer to shop at Amazon rather than local retailers, and that's before you add Amazon Prime to the bargain.

In America, a $US99 ($129.50) Amazon Prime annual subscription offers free two-day shipping on millions of eligible products, helping secure custom loyalty in a cut-throat market. In some cities Amazon Prime Now even offers two-hour express delivery on thousands of items.

To further sweeten the deal for US Prime subscribers, Amazon throws in free access to its Prime Music, Prime Video and Twitch Prime subscription services along with some free books and magazines.

In Australia, Amazon Prime is confirmed for "mid 2018" but all that Amazon will reveal at this point is that it will offer "exclusive delivery benefits".

An Australian Prime subscription will definitely include Prime Video and Twitch Prime, with Amazon Music a likely addition if it is launched in Australia alongside the Echo smart speakers early next year.

Amazon's local ecosystem remains hamstrung until its Alexa assistant is supported in Australia. Alexa underpins the Echo speakers and many other smart home devices. While we wait, Amazon is giving arch rival Google Home an even bigger head start in Australia as the search giant continues to forge new retail relationships, such as Google Home support for Officeworks.

Without Alexa, Amazon is also hamstrung in the lounge room. For now Australians can only buy the Alexa-less Fire TV Basic streaming media dongle, missing out on the cheaper yet more advanced Fire TV players available to US customers.

Australians can register their interest in Amazon Prime, but it's unlikely that we'll all enjoy the same delivery benefits considering our sparse population. The divide between city slickers and country folk is already reflected in Amazon's Australian delivery rates.

For now free shipping is available on orders direct from Amazon Australia worth more than $49, but these deliveries take up to a week to arrive.

Next-day "priority" delivery is available in Sydney, Melbourne, Brisbane, Adelaide and Canberra for $9.99. Amazon will even deliver on Saturday in these eastern capitals, meeting the needs of busy households.

Meanwhile shoppers in Perth and regional cities in Victoria, NSW and SA pay $11.99 for one-to-two day delivery. More remote parts of the country will pay $19.99 for one-to-two day delivery. For less urgent deliveries, $5.99 "expedited" delivery of two-to-seven days is available in the eastern capitals, with other Australians again paying more for this service.

These delivery rates are roughly on par with other local retailers. But the real challenge for the foreign raider is replicating its same-day Amazon Prime Now service, says Will On, co-founder and joint CEO of Australian delivery start-up Shippit.

Amazon aims to offer three-hour delivery from its Melbourne warehouse, On says, but the data driven retailer is waiting to analyse and optimise its high-volume Australian delivery routes before it makes a move.

"Today's launch is Amazon's first step," On says. "They'll eventually launch Prime as they will know which routes and cities are the most active; data points will include repeat buyers, shipping locations and what suppliers are being purchased from."

Amazon's impending launch has forced local retailers to refocus their delivery efforts and over the last few months several have taken advantage of Shippit to launch three-hour delivery in the major capital cities.

"Same day delivery is shaping up as the new battleground for online shopping," On says, "and Australian retailers need to respond if they want to ensure that Amazon doesn't push them aside."