Probably because TalkTalk are the only "free" ISP in the UK, because they give you the broadband for nothing along with your normal phone line (and on your phone line, all calls to all other TalkTalk customers are free too). Seriously, I used TalkTalk for about a year just because they gave us a year's free international calls to try to keep us there but after that there's NOTHING to keep you on them (their customer service is and always has been atrocious but hey, I was getting free international calls to my wife's father in the US / Kuwait, free calls to her mother in Cornwall, free calls to half-a-dozen friends and phone bills on the order of £2 per quarter). They would also have thrown in free broadband too, but use their broadband? You've *GOT* to be joking! TalkTalk has THE WORST reputation of any ISP ever because it's basically "thrown in for free" in order to try to keep you with them. When our "free international calls" expired, and TalkTalk refused to deal with either me or my wife (which is hilarious, because we're the only one who lived in that house and paid the bills!) it took *minutes* to get us put back on BT (did it online with two clicks). It took about 2 days to get the ADSL moved over to PlusNet, too. We didn't even *need* any co-operation from TalkTalk whatsoever - the companies knew how terrible they were and just did it for us, automatically in the case of BT.
Seriously, any ISP is better than TalkTalk and if you're *relying* on your broadband to do business, that's a bit dodgy. Stop being a cheapskate - you can move to another ADSL ISP in a matter of days without having to lift a finger, from silly prices like £5.99 a month (PlusNet). If you have an ADSL line, ANY ISP will gladly take that up for you in a matter of minutes. Hell, a pay-as-you-go 3G dongle costs £15 a month (or £2 a day on a day-to-day package) for 2Mb access (3Gb limit - T-Mobile). Sorry, but if you're doing business online and you can't even get an ISP to get you online, let alone having a *business* broadband connection, and can't switch, and choose the "free" ISP's instead of the cheap ones, and can't be bothered to do anything about it after "weeks" then you really don't care about it.