Wow, good question. But if they offer it and you want to purchase the sofa, then act on it.
I'm buying a crib and crib mattress (both on sale!) from WalMart.com and both are being shipped for only 97-cents each. I'm not even going to complain or question it...lol...I'm just going to accept it and save the money.
It could be that they have an overload of the same sofas that they want to get off their hands and they figure the low shipping is an incentive to draw in more consumers. That's my guess.
What TeensMom07 said. Plus, with the volume of stuff they're shipping they may have worked a deal with the shipping company for a discount rate. They'd be a huge client, and the company would eat some of the cost to get/keep them.
Don't ask that question, because if I could get a sofa shipping for a 1, then why not! But I know what you mean, it seems crazy but I ordered a desk and the shipping was free! I love Overstock.com Hope you love your sofa!