Digidesign was the first company to market a DAW that was stable. There are still a lot of the SDII and 442 systems around being used for voiceover work.
To suggest that Digidesign gives away tons of free stuff is not really accurate. All of the DAW companies provide partners with NFR copies of software. I get software on a semi-weekly basis from many companies.
Today, most DAWs are very capable of producing commercial cds. This was not the case 12 or 13 years ago. If you look back to early versions of software and compare what Digi was doing back then it's easy to see why they were able to gain a stronghold in the market. Once something has market share, they're pretty much set as long as they provide good support and continue to make a good product.
In 1995, most engineers started learning ProTools and (just like many people here got into Sonar a few years ago) now they're used to it. If you buy plugs or interfaces you know things are going to work becasue they're digi approved. You don't have the guesswork of choosing a motherboard, video card, etc... Just get a G5 and go.
To the guy that says most HD systems are now running on PC - you're wrong. Maybe you have seen HD PC systems, but Digi and Apple have worked together for years and while it is possible to run a good HD system on XP, if you buy HD chances are you buy a Mac.
ProTools interfaces with Avid products so perfectly. This is another reason PT is not going to lose pro market share. How many cds today come with a dvd that shows the record being made or some extra stuff? One of the big reasons this is done is because it's so friggin easy to take the ProTools session and throw it into an Avid system with the video. Production costs are pretty low and it makes people more likely to buy a cd rather than kaza it becasue of the extra features and it also makes the record company more money. This is one thing I have begun to explore getting into in my own studio and it will be a very simple process - all you need is PT or Nuendo and a couple video cameras.
All the talk about Cakewalk not having integrated hardware is interesting. Everytime they have tried this it has failed (remember the Peavey partnership?). Nuendo and Yamaha are the only company out there that is seriously poised to give Digi a run for their money.
I would LOVE to see Sonar make a video version with the kind of functionality that a Nuendo or PT has. I don't know if those features are worth adding when you consider that many people who use Sonar are not interested in video post work.