I called comcast to get this number to do not call.  Make sure you tell comcast that you do not have comcast/voice right away,  they will still block it for you.  I'll be back if comcast f**** up.

Received 15 calls from this number in a month! Answered it once, no one on the other line.  Just answered it again, and it was a company calling "on behalf of Comcast" trying to sell more services.

Have been getting calls from this number for almost a month. Nobody answers on the other end.

Updates:

Forgot to mention in my previous post that I am on the Do Not Call list.  Just got another call from this number.  I answered, and of course the line went dead.

Now when you call back this number there is a recorded message (no more busy signal) - and I confirm what Rob said - it's Market Link due to Comcast and they're calling about some dam promotion of course.

I called Comcast and they said "it's not them" and they "do not do business with Market Link" and "this can't be because of Comcast" and "it would be illegal to do so".  The representative suggested I take legal action against this number.  ha.  whatever.  goodbye.

I then added this number to my "block calls" option with my cellphone provider.

Then, I called Comcast again, and got a different representative (I have learned from past experience that there's no use asking for a manager when on the call with a first line rep for Comcast.)  I told my same story, I'm on hold now as the rep investigates.  The rep said that he is going to add me to the "do not call" list - I said wait, I'm on the government Do Not Call list - and the rep said that Comcast has their own do not call list (apparently the government list does not matter when you are a customer? I could scream...).  

After being on hold with Comcast for 15+ minutes, the rep came back, said he talked directly to a Market Link Supervisor, and he had my number removed from their call list.  He said this wouldn't take affect for 30 days (of course!) but it would be resolved.  The rep also confirmed that he has taken me off of Comcast's "call list" that they give out to telemarketers.  The rep was nice, but that doesn't absolve Comcast of anything.

This is absolute bullshyte.  Regardless of this incident "resolution" (not proven yet), I will find a new provider, Comcast has lost me as a customer.  Speak with your wallet if you can - that's the only way, eh!

It's a company called Market Link calling for Comcast about promotions. No option if you call them back to be removed from their calling list though, just a message about who they are.

I have received multiple calls over the last 6 weeks from this number as well (sometimes single calls, sometimes 2 calls in a row); no response from caller when I answer, and no voice mail when I don't answer, and a busy signal when I call back the 855#.  I submitted a complaint at the FCC site mentioned on a previous post.  

I can't confirm that it is comcast, but I do believe so based on other comments and my comcast history.

I've been getting calls from this number for weeks. When I picked up, it was blank. It now calls me several times a day, sometimes immediately after just calling.
On the bright side, I get to try out my phone's Reject List feature.

Been called by this number for months. Never anyone of the other end.. then the one time I decide to give it to my boyfriend to answer out of my frustration, its Comcast tryin to upgrade me for free. Calls stopped for a while and now they are starting again 2 in a row.. with no answer. Very annoying.

I got two calls from this number back to back, I didn't answer it. But when I tried to call it back it had a message stating they were a marketing company calling on behalf of Comcast to tell me about a new deal. Comcast herasses people more than any other company.

Number called me twice. No one responded when I answered either time. It has to be Comcast; only they would do stupid stuff like this.

Number keeps calling and there is no one on the other end. WTF?

again 2 calls in a row - no message left.

Ditto - 2 calls in a row - no message left.

I have received 5 calls from this number in one week.  2 times on one day.  Tried calling it back and just a busy signal.

http://www.fcc.gov/complaints     website to file a complaint

this number has been calling almost every week for 3 weeks, super annoyed, never says anything nor leaves any message. how to disconnect this number of complain about it?

I got several phone calls from 855 823 6608, all blank, then this am, got one that tried to upsell my comcast service, called comcast, they didn't deny it, but didn't agree it was them either . . I complained about it . .have no idea it IS them or not . .

Number keeps popping up on calls and no one is there.

called two days in a row. i answered the second time and they calimed to be my cable provider. Except when i asked who it was he stated his name was Alex from Comcast store numbe3747482. Ohio 28488..once he got that far and no company lables themselves that way i figured it was some call from Cambodia trying to rack up fees....im still looking into this

Received call two days in a row from this number aound the same time of day, never answered it and they never left a message.

Got a call on July 29th at 9am and again today at 2pm PDT, no voicemail. I never picked up, so don't know who it is.

unwanted, no message call, they (it) hung up after I said hello

Same blank call

blank call