No, I've had months when I had a sustained 60-80 mbps for weeks.
A company buys bandwidth for around 0.8-1$ a megabit, in volume... let's say $900 for 1 gbps 95 percentile. But keep in mind this company has servers in a large European datacenter and a large percent of the traffic is passed through free peering links with various other European datacenters so that traffic is almost free.
It's easy to put 30-35 servers in a 42U rack with a switch linked to the core router through a 2gbps (pair of standard 1gbps cables) or a 10 gbps fiber.
The company can give 10 TB on 1 gbps for the same price as 100 mbps unmetered because the user would know to be careful not to push 1 gbps all the time (10 TB is basically an average of 30 mbps throughout the month), the excess is something like 1-2$ per 10 GB or something like that (unless you mail them and choose to pay something like 30$ for extra 20 TB).
The real 1gbps unmetered links (330 TB a month) are about 400-600$ a month for bandwidth alone at this company. It's a gamble on their part, they gamble a large percent won't saturate their gigabit links and eat into their profit. For such bandwidth usage, you'd need a server with good I/O so that means either lots of RAM, or lots of drives, or SSD drives.. and renting such server cost money and have a higher profit margin compared to cheaper servers.
They offer (or used to offer a few months ago) some cheaper 1 gbps unmetered links for around 2-300$ a month but you have to agree not to rent such servers and use them for some particular cases like CDN, radio streaming, youtube style sites etc because the uplink can be saturated easily and if you push 1gbps for long time it affects other servers in the rack. On average, you get 200-500 mbps at any time, so it's still good value for money if you need a server that has occasional bursts of traffic (for example Dave posting a new video every few days, or the amphour show, or pushing a patch for a free software you develop etc etc)
Hosting your own podcasts on such server or offering the youtube video collection to download etc would totally be OK.
ps. If anyone cares the company is Swiftway ... the offers on their sites aren't that great, see the WHT offers here if anyone's curious :
http://www.webhostingtalk.com/showthread.php?t=1306222&highlight=swiftway