IF an ability to make your rivals angry is any measure of business success, Charles Dunstone and Carphone Warehouse had a great week.

At Wanadoo, UK chief executive Eric Abensur was said to be “hopping mad” at the copious media coverage given to the launch of “free broadband forever” by Carphone’s Talk Talk subsidiary. Dunstone even merited an approving editorial comment in The Sun.

Lee Strafford, chief executive of Plus Net, a much smaller internet service provider, had still more reason to be cross. Shares in Plus Net fell as much as 30% on Monday and Tuesday when one analyst suggested it was among the most vulnerable to the Carphone assault on the broadband market.

“It was an overly dramatic move,” said Strafford. “We are the most efficient service provider in this space. We can compete on a reasonable and profitable basis with Carphone where others might struggle.”

Dunstone’s rivals have a litany of complaints. Talk Talk broadband is not really free, they say, as it requires customers to pay £20.99 a month for line rental and a voice-calls package. On top of that, there is a £29.99 connection charge, the 18-month contract term, £70 early-termination penalty, 50p-a-minute charge for calling technical support — and a hidden 50p rise in what Talk Talk was charging for line rental.

Moreover, “free” broadband will be available only to the 70% of the population within reach of the 1,000 BT telephone exchanges where Talk Talk will install its equipment.

Although valid, these objections cannot disguise the fact that Talk Talk’s pricing is aggressively competitive. For the same package of 8-megabit- per-second broadband and unlimited landline calls, Talk Talk reckons it is about 60% cheaper than BT, NTL, AOL and Wanadoo.

Including capital spending and upfront losses, the broadband initiative will cost Carphone £110m this year. However, Dunstone expects a cash payback on his investment within four years, even if he adds only 1m customers to Talk Talk’s existing total of 2.6m.

The biggest risk, as Dunstone readily concedes, is Talk Talk’s ability to deliver what it has promised. Its website and call centres were overwhelmed last week as it struggled to cope with the huge initial demand.

Perhaps more significantly, rivals warn it may have underestimated the difficulties of getting its broadband equipment into BT’s exchanges and switching customers. The telecommunications adjudicator last week warned this process was running unacceptably behind schedule.

“This is not an automatic process,” said one broadband boss. “It’s very, very manual. BT will struggle because it is a new process for them, and they are having to cope with so many players all wanting to do the same thing.”