Just over one per cent of 3G iPhone owners used more than one gigabyte of data in their first month, according to Rogers. (Ed Ou/Associated Press)

Rogers Communications Inc. is revamping its data rate plans and extending a limited-time offer on the iPhone in order to spur sales of smartphones.

The Toronto-based company, Canada's largest cellphone provider, on Thursday said it will extend the $30-a-month data plan — which lets owners of iPhones and other smartphones download up to six gigabytes a month — until the end of September. Rogers announced the plan, which was to expire on Aug. 31, in July when it launched Apple Inc.'s 3G iPhone.

Liz Hamilton, spokesperson for Rogers, said the plan is being extended so that buyers of the BlackBerry Bold, which was released last week, can take advantage of it.

Rogers will introduce a $25-a-month data plan for the iPhone and other smartphones on Oct. 1 that will allow 500 megabytes of downloading per month, which will be bundled with a three-month promotion of unlimited usage. Another plan will allow one gigabyte of usage for $30. The plans will also be applicable to aircards, which are used to connect laptop computers to the internet over a cellphone network.

Phone customers must also take a voice plan, which start at $20, and pay a system access fee of $6.95.

The new data plans are the result of monitoring iPhone customers' usage since its launch, Hamilton said.

"We learned a lot," she said. "We were educated by customers by what they wanted and we were educated by customers by what they used."

Hamilton said just over one per cent of iPhone owners used more than one gigabyte of data in their first month, while about 95 per cent of owners used less than 500MB — findings that are consistent with tests performed by CBCNews.ca.

Rogers was heavily criticized for the initial rate plans it had announced for the iPhone ahead of the device's July 11 launch. The company first offered a basic plan that allowed only 400MB of downloading per month, but was forced to introduce the lower-priced 6GB just days ahead of release after more than 60,000 people signed an online petition in protest.

Unlike other cellphone carriers, Rogers is allowing customers to "tether" their smartphones, or connect them to a computer and use them as a modem.

The company is also rolling out a "peace of mind protection plan" on Oct. 1, which will allow customers to get a better idea of how much data they are using. Customers will get periodic free incoming text messages warning them when they cross certain usage thresholds, such as when they have downloaded 80 per cent of their monthly data allotment. Also, excess usage charges that come into effect when the customer exceeds their monthly limit will be capped at $100.

"Customers want to have some tools to give themselves predictable costs," Hamilton said. "You know those stories out there, every now and then you hear about them, that are really poor, terrible customer experiences where somebody's got a five-figure data bill because their kid went and watched movies or something where they weren't sure of the data usage, that's not going to happen."

Rogers' iPhone is still one of the most expensive iPhones overall in the world by virtue of the mandatory three-year contract customers must sign, according to CBCNews.ca's iPhone iNdex. On a monthly basis, however, the cost of Rogers' basic plan — currently about $60 US — is below the global average of $71 US.