There's a slight difference. Billboards don't help support anything of value to you (namely the road you are driving on). They are advertising for the sake of

There's a slight difference. Billboards don't help support anything of value to you (namely the road you are driving on). They are advertising for the sake of advertising. Commercials on radio/TV/web fund the content you are enjoying. Of course you can flip the channel or have AdBlock or whatever, but you're actively taking revenue away from the creator. You may not have a problem with that (I certainly don't).