Generally speaking, US retailers seem to have adapted to Twitter more effectively than their UK counterparts, with some great examples of successful engagement with customers on the site.

Dell and Zappos are two firms that have often been given as examples, but there are plenty of others. For example, Threadless has managed to acquire an impressive 90,000 followers on Twitter by running competitions to design T-shirts.

I listed UK retailers on Twitter last week, and it was hard to get a list together, and many of the big names are missing. Creating a US list has been easier, but if I have missed any, let me know…

Amazon: http://twitter.com/amazon

Amazon Deals: http://twitter.com/amazondeals

American Apparel: http://twitter.com/americanapparel

BirthdayInABox: http://twitter.com/BirthdayInABox

Best Buy: http://twitter.com/BestBuyCMO

Build a Bear: http://twitter.com/buildabear

Buy.com: http://twitter.com/Buy_com

Dell Outlet: http://twitter.com/DellOutlet

Dunkin’ Donuts: http://twitter.com/dunkindonuts

eLuxury: http://twitter.com/eLUXURY

Etsy: http://twitter.com/Etsy

Fitfuel: http://twitter.com/fitfuel

Ford (Head of Social Media): http://twitter.com/scottmonty

Geeks.com: http://twitter.com/computergeeks

JCPenney: http://twitter.com/askjcp/

MagicHat: http://twitter.com/magichat

Motorola: http://twitter.com/motodeals

NeweggMall: http://twitter.com/NeweggMall

Overstock: http://twitter.com/Overstock

PacSun: http://twitter.com/PacSun

PawLuxury: http://twitter.com/PawLuxury

PetsMart: http://twitter.com/PetSmartTLC

Starbucks: http://twitter.com/starbucks/

TJ Maxx: http://twitter.com/tjmaxx

Threadless: http://twitter.com/threadless

Urban Outfitters: http://twitter.com/UrbanOutfitters

Whole Foods Market: http://twitter.com/WholeFoods

WineEnthusiast: http://twitter.com/WineEnthusiast

Woot: http://twitter.com/woot

Zappos: http://twitter.com/Zappos