sentences:  With the release of TurboCAD v2 DOS and v1 Windows in 1993, IMSI decided to begin using direct mail campaigns as a means of cost effectively increasing its user base and over the next two years became the primary advertising technique.Revenues for direct mail sales of TurboCAD grew to over $20 million annually in 1993, with successful prospect direct mail campaigns being sent out on a nearly monthly basis in the U.S., Canada, UK and Australia.In 1993, IMSI released the first Macintosh versions of TurboCAD – Standard retailed for $195, while Professional retailed for $495 and offered 3D, wireframe functionality.