If you're meaning in the "PVRs let people skip commercials" sense, well, you're seeing their adaptation now - from single 15 or 30 second spots that are more effort to jump through than to watch, through crap on the bottom/side/corner of the screen (prediction for the next big TV advertising "innovation": it won't just be station/program promos, and they'll argue it doesn't count towards ads/hour because the program is still on...), right through to product placement. And PayTV is only a year or two behind FTA in that respect - you pay your $60~$100/mo now, and you still get ads during programs, watermarks, and station promos over the credits.
Firstly, the number of ads per hour is less - including station promos, it's generally regulated to 10~15 minutes per hour, as opposed to the unregulated 15~20 here.
Secondly, the breaks are less frequent - usually 1 per half-hour show / 2 or 3 per hour show, as opposed to 2 or 3 per half-hour show here.
And thirdly, they don't have the artificial Pay / FTA divide caused by political pandering that we have here. PayTV fights for market share with FTA by offering breadth of content and international sport; FTA fights back with local programming and better quality, and the playing field is starting to level up with digital multi-channelling and intermediate services like TopUp TV (OK, so it keeps doing its phoenix-trick, dying and reviving ).
(Interesting to note too that, unlike here, FTA generally doesn't pay for carriage on Pay networks in the UK, Europe, and the USA - offering them carriage for free is seen by the PayTV operators as a way of getting people off FTA broadcasts & onto their platform, and by the FTA networks as expanding their reach. In fact, in the US I believe the FTA stations are starting to think they should be paid by the Pay networks! )
Or, to summarise : In my opinion, technology is reducing most of the differences between FTA and PayTV - almost to the point where they can just be treated as delivery mechanisms, not something special in their own right - and the rest are political, not technical. And we have more artificial, commercially-motivated, politically-manipulated, and legislatively-enshrined differences here - simultaneously pandering to and crippling both the FTA and PayTV lobbies - than anywhere else in the world. That's what's making the FTA model unsustainable, at least in the short to medium term. And it's not a Good Thing...