Summary Box: Netflix bolsters video library

GOOD FOR NETFLIX: Netflix’s Internet video service is adding more marquee attractions. As part of an effort to offer more exclusive material, Netflix locked up the right to show “The Artist” and other movies from The Weinstein Co.

BAD FOR NETFLIX: Comcast unveiled plans to undercut Netflix with a less expensive version of a service that will stream old TV series and movies to devices with high-speed Internet connections.

INVESTOR REACTION: Some investors have long worried about Netflix losing its early lead in Internet video as more rivals enter the market. Netflix’s stock fell nearly 4 percent on Tuesday.