The most compelling reason, I think, is the ease with which you can get up and running if you need to switch. Your computer crashes, or you’re away from it. Or you’ve bought a new computer. Suddenly you no longer need to find your RSS feeds file. Your email settings. Import old mailboxes. I installed Vista on a new computer just now and (after a Vista crash) I was checking my email and reading my feeds almost immediately. That never happened before.
Google is basically riding the wave that Microsoft had hoped to ride. If you’re using Gmail, you may as well use the Google Reader. And Google Docs, and the Calendar, because they’re all a mouseclick away and don’t require any more signing in. In fact, you can have everything you need up and running within a minute. Compare that to installing an email client, an RSS reader, an Office suite, a PIM for the calendar, and then importing all the settings necessary, and you’re talking about adding on another hour unless you’re a really well-organised person.
There’s another obvious reason: They’re quicker. Ever tried to add an event to Outlook faster than to Google Calendar? Ever tried to send an email quicker than with Gmail? I haven’t timed myself, but anything that shaves a few minutes off my day is going to make itself indispensable pretty quick.
I’m now using all these tools, and I never thought I would. I don’t like the privacy issues, and I don’t like relying on a company that thinks calling something in perpetual ‘beta’ is an acceptable course of action, but I can’t resist. I tell myself it’s just a phase, and that I’ll soon switch back to my trusty email client and RSS reader. But it’s probably never going to happen. I may not stick around forever with Google’s offerings (let’s face it, Gmail and Google Reader need a lot of work before they’re A grade) but I have a feeling I’ll never go back to standalone.