After a strong start over the Thanksgiving weekend, the traffic to the top 500 retail websites continue to increase every week throughout the 2011 holiday season as compared to last year.

The highest increases year-over-year for daily traffic took place on the day after Christmas where traffic was up 31% over last year and Cyber Monday where traffic was up 29%. Total visits reached the highest level of the holiday season on Cyber Monday this year, displacing Black Friday.

One driver of post Christmas traffic is always shoppers seeking out after Christmas sales & discounts, especially among those that received gift cards. If search behavior is any indicator, there were plenty of gift card buyers out there and along with recipients looking for ways to spend them. Early predictions from the NRF’s 2011 Holiday Consumer Intentions and Actions survey, expected holiday shoppers to spend an average of $155.43 on gift cards, the highest amount since 2007 and up from $145.61 last year. Search queries that included variations of ‘gift card’ started to increase the week before Thanksgiving and continued to grow each week. Last week, the share of search clicks that included ‘gift card’ increased 32% over the same week last year.

Last week the top search query to include ‘gift card’ was ‘kindle gift card’, most likely a companion gift to the many Kindles given as gifts this holiday season. Versatile, broad usage gift cards like the American Express gift card and Visa gift card were also among the top variations along with iTunes, another holiday favorite. Shoppers may have also been using their gift cards to purchase holiday gifts with two appearances of ‘balance’ in the top 10 variations.