That's the big question that none of us probably have an answer to. Like PG said about auctions: "a startup that wants to do this has to expend more effort on their strategy for cracking the monopoly than on how their auction site will work" and like he said about dating sites "if you want to do a dating startup, don't focus on the novel take on dating that you're going to offer. That's the easy half. Focus on novel ways to get around the chicken and egg problem."

Building a better CL isn't such a hard thing. The hard part is overcoming the momentum that CL has or in your case (since you want to go for people in rural areas) figuring out how to get people using it before there's a reason to use it (i.e. other people using it).

So, the chances that your site will succeed aren't wonderful. It's not that it isn't a worthy site, it's that there's a high level of random chance involved in whether a site like this succeeds. Success for a web office suite will be based on features, polish and the like. Success for your site will be (mostly) determined by whether other people use it since the majority of the value will be the user contributed content and not your code.

But, in terms of the code:

* Better search. CL only matches whole words as far as I can tell and it's just not great. Do it better. Get people to what they want more easily.

* Logins. I don't like having to create logins and until you're big don't put that hurdle in front of people. When your site has a million users, they will see the value of an account. Right now, an account is another reason not to use your site. Why should I register for a site with no one on it? However, if I can just post without registering, well, I might. Maybe offer the option of either ala CL.