Very well known, they bring in Millions and Millions of dollars per month. If a part of your factor of picking a host is whether or not you rely on them to be there forever - 1and1 is definitly the choice. They have 20 page inserts in world-wide magazines, huge ad's on many web pages, they even gave away 5 free years of hosting to anyone who wanted it not too long back. However, their prices are not the lowest.
I allways assumed that 1 & 1 were an excellent company, and I automatically assumed they had an excellent reputation because they *do* sell millions of domains, and they do manage millions of domains and they look professional and have alot of advertising, so I thought they *must* be excellent. I thought that *until* I listened to what people on this forum were saying so I then checked through the threads and checked up on google and I personally have chosen www.123-reg.co.uk instead of 1 & 1.
In fact that is the second company I have avoided directly thanks to this forum. The first one was the famous company known as www.datapacket.com. I have thankfully missed them *both* all thanks to the excellent reviews of the good folk on this forum.
The only experiance I have had with 1&1 was with a domain registred by one of my customers. The control pannel was not proplerly changing the nameservers, after 3 emails and 2 calls, 2 weeks later, they got one of their guys to manually update the info. :/
The only experience I've had with them is clients transferring from them. From my own experience, they are *really* slow to do domain changes. I can't say anything about their hosting, but I'd stay away from them for your domain name.
Former owner of A Small Orange New owner of <COMING SOON>
That is exactly the same kind of criticism I heard, nothing *that negative* about the hosting side, but they have very bad/slow customer support if you want to change your domains away from them, and slow to get anything done.
You'll find everything you need to know about 1&1 service and support by doing a quick search here. Slow Crawl and Not Available seem to be the typical modes of support provided. It didn't work for me, but some people have very good things to say about 1 & 1 service. Support issues, however, are legendary.