To build markets you have to go out, make some mistakes, find what works, then build upon it. And that costs money. Once you realise that the revenue from a major Microsoft application is comparable to the sales of AutoCAD, the invisibility of AutoCAD is even more inexplicable since Microsoft's margins are the same as Autodesk's. Microsoft isn't doing all that aggressive marketing by spending more on a percentage basis. They're either doing less of the things that don't get them in front of the customers, or they're getting more for their money.
Advertising is, of course, the last resort of the communicator.
Autodesk was able to promote AutoCAD in the early days with very little direct advertising by gaining editorial coverage in a wide variety of publications. A five or six page story about a user's success with AutoCAD delivers many times the impact of an advertisement at a fraction of the cost. These days, however, AutoCAD applications have become far more common and more imagination is needed to get the attention of the press. Imagination is something that's never been in short supply around Autodesk, yet we seem to consistently squander the visibility it gains us through lack of follow-through. One of the reasons I started the cyberspace project was to create a high-profile, exciting technology project to make the company stand out in the industry.