I agree that many desktop apps can't be entirely replaced by web-based equivalents. However, if a webapp can provide 80% of the features of a similar desktop ap

I agree that many desktop apps can't be entirely replaced by web-based equivalents. However, if a webapp can provide 80% of the features of a similar desktop app but with a much lower barrier to entry (nothing to install, cross-platform) and additional web-oriented features (collaboration, publishing, Facebook intergration, etc), this webapp can potentially capture a large market share. Google Docs is a good example -- it will never do everything that MS Office can do but it's easy to use and it's certainly good enough for many users. Desktop apps still occupy a niche, but the Web has made this niche much smaller than it used to be.