Question

Looking at a lot of web applications (websites/services/whatever) that have a ‘streaming’ component (typically this is a ‘Social’ app): Think: Facebook’s ‘Wall’, Twitter ‘Feed’, LinkedIn’s ‘News Feed’.

They have a pretty similar characteristic: ‘A notice of new items is added to the page (automatically assuming via a background Ajax call’, but the new HTML representing the newest feed items isn’t loaded to the page until the users click this update link.’

I guess I’m curious if this design decision is for any of the following reasons and if so: could anyone whom has worked on one of these types of apps explain the reasoning they found for doing it this way:

1. User experience (updates for a large number of ‘Facebook Friends’ or
   ‘Pages’ or ‘Tweets’ would move too quickly for one to absorb and
   read with any real intent, so the page isn’t refresh automatically.
2. Client-side performance: fetching a simple ‘count’ of updates
   requires less bandwidth (less loadtime), less JS running to update
   the page for anyone whom has the site open, and thus a lighter
   weight feel on the client-side.
3. Server-side performance: Fewer requests coming into the server to
   gather more information about recent updates (less outgoing
   bandwidth, more free cycles to be grabbing information for those
   whom do request it (by clicking the link). While I’m sure the owners
   of these websites aren’t ‘short on resources’, if everyone whom had
   Twitter or Facebook open in the browser got a full-update fetched
   from the server every-time one was created I’m sure it would be a
   much more sig. drag on resources.
4. They are actually trying to save resources (it takes a cup of coffee
   to perform a Google search (haha)) and sending a few bytes of data
   to the page representing the count of new updates is a lot lighter
   of a load on applications that are being used simultaneously on
   hundreds and thousands of browser windows (not to mention API
   requests).

I have a few more questions depending on the answer to this first question as well…so I’ll probably add those here or ask another question!!

Thanks

P.S. This question got trolled off of the ‘Web Applications’ site — so I brought my questions here where they’re not to ‘broad’ or ‘off-topic’ (-8

Answer 1

Until the recent UI changes to Facebook, they did auto-load new content. It was extremely frustrating from a user perspective, as you’d be reading through the list of your friend’s posts and all of a sudden everything would shift and you’d have no idea where the post you were just reading went.

I’d imagine this is the main reason.