Chief Executive Alan White said the firm's average customer, a 57 year old woman, was more financially resilient than the typical shopper and was flocking to new designer ranges such as corsetry by fashion guru Gok Wan and dresses by Caryn Franklin, a presenter on television programme "The Clothes Show."
"These are people who have been almost disenfranchised by the High Street in terms of the clothes they can buy. Having it in their size is a big tick. Then being able to find some upmarket clothing, and some designer ranges, in their size is a double tick," he said in a telephone interview.
But White said external events, like the global banking crisis, were making him more cautious about prospects.
N Brown, whose catalogues include Simple Be and Oxendales, said pretax profit rose 20 percent to 40.8 million pounds in the 26 weeks to August 30, above an average forecast of 37.6 million in a company poll of five analysts.
Sales rose 12.6 percent to 322.8 million pounds, and had stayed robust, up 11.8 percent, in the five weeks to October 4.
White said sales growth was likely to moderate over the second half and that he expected analysts' full-year profit forecast to stay around 83 million pounds.
Gross margins, a measure of profitability, fell 80 basis points in the first half, due to increased sales from newly recruited and younger customers, who have a higher credit risk.
The group said the rate of bad debts, comparing similar customers year-on-year, was showing little deterioration, but it was tightening credit policies as a precaution.
Online sales, which are cheaper to process than telephone sales, leapt 45 percent to account for 33 percent of the total.
"While we accept that an increase in bad debts remains a risk we think the Web and other internal factors will over-ride this issue due to low average outstanding balances, an older less borrowed customer base and excellent credit controls," Landsbanki analysts said, keeping a "buy" rating on the stock.
The shares, which have beaten the general retail index by 50 percent this year, were up 1.6 percent at 200 pence by 8:30 a.m., valuing N Brown at 615 million pounds.
The interim dividend was lifted 5 percent to 2.78 pence.