Why do they still call it Black Friday when more obsessed holiday shoppers are hitting stores on Thanksgiving Day? Because Black "Can't I Just Finish My Thanksgiving Pie In Peace?" takes up way too much space.

Wal-Mart (WMT) launched the latest strike in its war on Thanksgiving last month, when it announced that it would open at 8 p.m. on Thanksgiving evening to customers forming in-store lines for its most coveted discount products. For those who prize Thanksgiving traditions like dessert, digestion and tryptophan-induced slumber, that's a full two hours earlier than the store's 10 p.m. start last year.

The top brass at Target (TGT) didn't push that retailer's doorbuster start time from midnight last year to 9 p.m. this year just for personal amusement. According to the National Retail Federation, 28.7 million people did their Black Friday shopping on Thanksgiving Day last year. That's still less than a third of the roughly 86 million shoppers who took to stores on Black Friday itself, but it's still up from the 22 million who took time from their turkey or Tofurkey dinners to go bargain hunting on Thanksgiving 2010.

They didn't have to bundle up and huddle outside of big-box stores to do so, either. Market research firm ComScore (SCOR) found that online spending on Thanksgiving Day rose 18% in 2011 to $479 million from $407 million a year earlier. Sure, lots of that traffic was Amazon shoppers who didn't really have a brick-and-mortar option, but ComScore's Thanksgiving and Black Friday Top Five also included Wal-Mart, Best Buy and Target, who wooed overstuffed Thanksgiving shoppers with deals they could access from devices balanced on their swollen stomachs.

But do retailers' Thanksgiving intrusions really increase sales, or just pull them from some softer part of the Black Friday weekend schedule? The NRF sees an overall gain, with its count of store traffic from Thanksgiving through the end of Black Friday weekend rising from 212 million shoppers in 2010 to 226 million last year. The nearly 7 million more people in stores on Thanksgiving helped, but about the same number joined the ranks for the rest of the stretch.

They didn't exactly shy away from online orders for the rest of the holiday season either. ComScore saw a 16% increase on Thanksgiving weekend overall in 2011, including a 26% spike in Black Friday shopping. While that 18% bump in Thanksgiving Day spending is impressive, it still trails both the growth and haul of Cyber Monday (up 22% in 2011 to $1.25 billion) and Green Monday (up 19% to $1.13 billion) and doesn't come close to the $1.1 billion spent on Free Shipping Day.

As long as retailers are taking increasingly larger bites of holiday spending by starting their Black Friday sales earlier on Thanksgiving night, consumers will continue to be tempted into taking that last cup of pudding or slice of pumpkin pie to go.