87% of tablet owners are using their devices while shopping for the holidays and plan to spend an average of $325 via their tablets, according to a new study by rich media firm Zmags. Nearly a third of tablet owners say they like to shop on their devices because it is convenient. 24% also like how tablets facilitate easy browsing and help them discover products via retailers’ sites, online catalogs and tablet apps.

50% of tablet owners say the couch is their favorite location for shopping; 20% say their bed, the study finds. They can also be found shopping at the kitchen counter, in a mall, at coffee shops and on public transportation.

“Only two weeks into the 2011 holiday shopping season and it is clear that tablet commerce is a critical and emerging channel for retail sales,” says W. Sean Ford, COO and CMO at Zmags. The survey of 238 tablet owners was conducted by Equation Research for Zmags.

Another survey on mobile shopping finds more m-commerce enthusiasts. Out of 66.9% of smartphone and tablet users who say they have already used their device to shop this holiday season, 35.1% say their mobile device has been an integral part of shopping, according to a survey of 332 users of smartphones, tablets or both devices, conducted by mobile research firm Prosper Mobile Insights. 52.7% say a smartphone or tablet has made shopping convenient, but they could shop without a mobile device if they needed to. Only 12.2% haven’t seen a benefit to mobile holiday shopping.

Of those who have used their mobile device to shop this holiday season, 25.1% say they would be extremely likely to recommend mobile shopping to a friend or colleague, the Prosper Mobile Insights survey finds.