tangor - 11:31 pm on Mar 13, 2010 (gmt 0)
The comparison of tv/radio to the web is valid to a point, but fails overall as tv/radio have long historical backgrounds as to operation and advertising models and has already dealt with this aspect of advertising several times (hence cable, direct, etc., pay models) few of which have been embraced by the web...yet.
In the web's short history ads are the newcomer and some resistance is to be expected. Additionally there is the secondary security/privacy issues which tv/radio do not introduce (unless mainstream media news is a trojan yet to be acknowledged).
A tv/radio is not the same as a personal computer where folks do work, communicate, maintain personal information, can be commandeered by malicious parties. Tv/Radio are passive set top boxes with no interaction to personal information (other than cable networks). I NoScript (block third party everything, scripts, and other material not originating from the intended site destination. Thus, I do see ads which are hosted on the visited site, but do not see adsense, adwords, affiliates, etc.