Although many Americans are still recovering from the busy holiday shopping season that included record Black Friday sales, Presidents Day discounts are expected to be even deeper.

Shop It To Me, a personalized online sales shopper, found that Presidents Day sales averaged 46.7 percent off apparel, shoes and accessories, outpacing those of Black Friday (the day after Thanksgiving), which averaged up to 42.1 percent off , and Cyber Monday (three days later), which saw discounts of 41.1 percent.

Tamra Feldman, Shop It To Me's VP of marketing, said that's from daily sales data from more than 150 online retailers in 2011 for women, men and children. The online site analyzes data from large department stores such as Nordstrom, Barneys New York, J. Crew and online boutiques. The site then can send daily personalized sale notifications to users based on their preferences, like brand and size.

Presidents Day ranks second just behind Labor Day as the best holiday to grab the steepest online apparel sales, said the company, based in San Francisco. Feldman said this was the first time the 5-year old company has compared holiday discounts to each other, although the company found that Presidents Day also had some of the deepest discounts in 2010.

Like Black Friday, retailers are launching Presidents Day online sales Friday before the actual holiday, Feldman said.

"So people with downtime will find great sales online," she said, adding that shoppers might want to act quickly. "I do think the best items won't last long or many sizes will be gone."

Shop It To Me compiled descriptions of Presidents Day sales and promotions from 40 retailers.  Among Feldman's favorites are those of J. Crew, which is offering a 20 percent discount off online orders of $150 or more, and Nordstrom, which is offering a 40 percent clearance on shoes, with free shipping and returns.

 Average Holiday Discounts, based on Shop It To Me's 2011 data

1. Labor Day: 48.4 percent off

2. Presidents Day: 46.7 percent off

3. Columbus Day: 45.2 percent off

4. New Year's Day: 44.2 percent off

5. Independence Day: 43.5 percent off

6. Memorial Day: 42 percent off