There are two reasons that come to mind immediately.
First, legally you can't use one online service to aggregate from other services -- every walled garden has clear TOS that prevent this. You can, however do the gathering and processing locally. After all, you own your own computer equipment and are solely responsible for how data is collected and presented there.
Secondly, and more importantly because of the history, you're trying to solve the problem using the constraints and assumptions that created the problem to begin with. You can't fix seven walled gardens -- by creating yet another walled garden.
Stand-alone targeted web apps are great for finding needs and servicing markets, but the nature of the net is monopolistic. That's why many of these stand-alones end up getting flipped. We need to break the technical backbone that keeps creating monopolies if we really want to get rid of them.
First, legally you can't use one online service to aggregate from other services -- every walled garden has clear TOS that prevent this. You can, however do the gathering and processing locally. After all, you own your own computer equipment and are solely responsible for how data is collected and presented there.
Secondly, and more importantly because of the history, you're trying to solve the problem using the constraints and assumptions that created the problem to begin with. You can't fix seven walled gardens -- by creating yet another walled garden.
Stand-alone targeted web apps are great for finding needs and servicing markets, but the nature of the net is monopolistic. That's why many of these stand-alones end up getting flipped. We need to break the technical backbone that keeps creating monopolies if we really want to get rid of them.