A backlog of 60,000 boot orders could grow to 100,000 by month's end, and the company is in the process of hiring 100 workers and purchasing additional equipment to catch up with demand. "We just can't make enough of them," said Tom Armstrong, L.L. Bean's chief merchandising officer. The rubber-bottomed, leather-topped "duck boot" has seen sales grow from fewer than 100,000 a decade ago to about 450,000 this year. Next year, the number is expected to top 500,000.