If you have a 4.5 Mbit/sec internect connection (3 bonded t1s) for example, just one user playing a full screen video can take over 75% of your available (download) bandwidth. If you have a mixture of data applications (VPN, MSTS/RDP/Citrix/Intranet) and general web use sharing the same pipe this can cause a real problem when 1 or more users fire up a video. At home users are often used to having 10 or 20 or more Mbits/sec of download speed dedicated to a single PC. They dont understand (or care) that their office connection may have considerably less available bandwidth.
I suggest having a broadband connection (FIOS, Cable, or DSL) for general web use, and a symmetric (t1, or metro ethernet) connection with a good carrier SLA for site to site VPNs, RDP, etc. The SLA for metro ethernet, t1, or bonded t1 should guarantee shorter time to repair than a entry level business class broadband service if there is a circuit failure. Its also possible in many cases to do QoS marking on vpn traffic that crosses a t1 based or metro ethernet based internet service whereas with Cable or Verizon FIOS, you cannot mark traffic and you will often be rate shaped in the cloud which can cause problems if you do not plan for this properly.
1. Small (regular size embedded) screen youtube.com video will take about 1.0Mbits/sec of bandwidth to play.
2. Full size (full screen) youtube.com video: 3.0 to 3.8 Mbits/sec.
3. Videoconference sessions typically take 1.5 to 3.0 Mbits/sec depending on the video quality.