Comcastoffers.com is an Authorized Comcast Dealer that will come up high on the list when you do an internet search. Note: they are not actually Comcast, but an "authorized Comcast" dealer... they sell you the service and then patch you over to Comcast itself.
A couple of things: Despite all their claims, it appears you'll actually get more and better deals if you go directly to the actual Comcast website.
Also, a big factor is their "rebate offer" and free modem and router. You'll be hard presser to get your actual "free" modem or router. After you place your order you quickly see that they've charged you $120... but don't worry, you can send in for a rebate card. The rebate card instructions will require you to cut up the boxes and fill out a bunch of paper work and mail them off to a third party rebate dealer... and please wait 6-8 weeks for a response. And of course 6 weeks later you'll get an e-mail from the rebate dealer saying your claim was denied. I got two different reasons for my claims being denied, neither made any sense -but good luck getting a hold of the rebate company.
Also, as part of the deal they will automatically enroll you in a "free" 14 day trail for REAL Superpass... they cover this part very quickly and even when you tell them you want no such thing, they apparently give you information, including credit card info, over to REAL. I'm still not sure what this offer is good for, if anything, but 14 days later they will start billing your credit card $15 per month. You then have to establish an account with REAL, when you go to cancel, they give you a number to call.... call the number, wait on hold, and if you are lucky you'll finally get a hold of someone in India that will try to sell you additional services... not only do you need to cancel this, but insist that they refund your credit card... if you are lucky they will give you a one time refund -but you have to demand it from them.
Beyond that, Comcast services itself sucks... both cable and internet. I've traded it in for Direct TV and Verison and now I pay less money for better service. However, if you are forced to use Comcast, make sure you order it directly from Comcast and avoid ComcastOffers.com like the plague.