The report, published in July, reveals a 1.4 per cent increase in seasonal chocolate sales between 1999 and 2004, which is equivalent to a 10.5 per cent decline with inflation taken into account.
Sales of seasonal chocolate in 2004, which included verified sales for all holiday products, stood at $3.4bn (€2.7bn), representing 22.5 per cent of the total $15.1bn (€12bn) US chocolate market.
The overall chocolate market increased 7.6 per cent in the time period, which represents a 5 per cent decline in real terms, says the report.
Some chocolate manufacturers are sidestepping seasonal restrictions on sales by "blurring seasonal lines" to make products that can be used for more than one holiday.
"Hershey's Kisses leverages a number of fourth-quarter holidays by selling bags of red, gold, brown and orange-wrapped chocolates. By not specifying 'holiday' on the wrapping, the product can be sold at Halloween, Thanksgiving, Fall Football, or Back to School. The same is true for M&Ms, which are sold in 'seasonal colours' that can be given for a number of holidays," says the report.
"The market is also 'channel blurring', which makes it possible to purchase seasonal chocolate, and indeed chocolate for any occasion, through myriad channels from the highest quality chocolatier to the dollar store."