Selling iPhone 4s on usell.com.is this a scam?

I seen the usell.com commercial so I went on the website and I seen bids for my iPhone. The highest bid was for $330 and i clicked on it. I signed it up, then they sent me an email saying that they will send me a uSell box in 3-7 days to ship my Sprint iPhone to them… Once they receive it, they said they will email me to notify that it is good, then send me my check for $330. Has anyone ever sold phones on this site before? Was it a scam? And how long did it take them to send your check after you have received the email?

Why buy a used phone of dubious condition when you can get one that is guaranteed to work from AT&T or Verizon.

YES, IT IS 100% SCAM.

The site owned by Upstream Worldwide Inc has been around for some 16 years, a pioneer in internet time, in those years it has accumulated complaints proclaiming scam:

Planned class action lawsuit?
http://www.newjerseyclassactionlawyer.net/usell-com-fraud-lawsuit/

http://www.complaintsboard.com/complaints/wwwusellcom-california-c479625.html

http://www.ripoffreport.com/cellular-phone-companies/usell-com/usell-com-my-gold-envelope-in-efb9a.htm

http://www.scambook.com/report/view/3906/USell.com-Complaint-3906-for-$125.00

Got $19 for an iPhone…
http://www.reviewstalk.com/complaints-reviews/usell-com-l5163.html

Vague gripes
http://www.scaminformer.com/scam-report/usell-com-usell-com-do-nt-do-business-with-usell-com-internet-c17987.html
http://www.scamfound.com/f13/usell-com-complete-scam-171997.html

The wise assumption is than people are out to rip you off, even on TV. Advertise on Craigslist.org to locals you can meet in person instead.

The same people appear to operate:
upstreamworldwide.com
uselldvd.com
sobredeoro.com
mygoldenvelope.info inactive, but the same mail in for cash scheme.

The majority of complaints about uSell date back to transactions that were made prior to June of 2011. The company has an A- BBB rating. All of the customer issues have been resolved and uSell is focused on its new business and providing customers with an easy and secure way of selling their unwanted electronic devices.

Depending on which buyer you choose, payment could be sent anywhere from 2 days to 3 weeks from the time they receive your package. They also offer different payment options, such as check and PayPal. Once you quote a device, click on the "see details" link under the offer to find out the buyer's terms and payment options.

If you have an issue with a current transaction, you are strongly encouraged to contact uSell directly at Support@uSell.com.