If there's a better place to ask this, please let me know.

Every time I build a new website/blog/shopping-cart/etc., I keep trying to do the following:

• Extract out common functionality into reusable code (Rubygems and jQuery plugins mostly)
• If possible, convert that gem into a small service so I never have to deal with a database for the objects involved (by service, I mean something lean and mean, usually built with the Sinatra Web Framework with a few core models.

My assumption is, if I can remove dependencies on local databases, that will make it easier and more scalable in the long run (scalable in terms of reusability and manageability, not necessarily database/performance). I'm not sure if that's a good or bad assumption yet. What do you think?

I've made this assumption because of the following reason:

Most serious database/model functionality has been built on the internet somewhere.

Just to name a few:

• Social Network API: Facebook
• Messaging API: Twitter
• Mailing API: Google
• Event API: Eventbrite
• Shopping API: Shopify
• Comment API: Disqus
• Form API: Wufoo
• Image API: Picasa
• Video API: Youtube ...

Each of those things are fairly complicated to build from scratch and to make as optimized, simple, and easy to use as those companies have.

So if I build an app that shows pictures (picasa) on an Event page (eventbrite), and you can see who joined the event (facebook events), and send them emails (google apps api), and have them fill out monthly surveys (wufoo), and watch a video when they're done (youtube), all integrated into a custom, easy to use website, and I can do that without ever creating a local database, is that a good thing?

I ask because there's two things missing from the puzzle that keep forcing me to create that local database:

• Post API
• RESTful/Pretty Url API

While there's plenty of Blogging systems and APIs for them, there is no one place where you can just write content and have it part of some massive thing. For every app, I have to use code for creating pretty/restful urls, and that saves posts. But it seems like that should be a service!

Question is, is that the main point of a website? Will everyone always need "their own blog"? Why not just have a profile and write lots of content on an established platform like StackOverflow or Facebook?