There are too many Web2.0 social bookmarking services.
So far I've succeeded in ignoring most of the ones that fail to make my life any easier, and thrived in the ignorance about the existence of the irrelevant ones.
Then I ran into a blog that displayed the following bookmark bar under each posting (image slightly cropped). Each of the tiny squares represent some service that ultimately will help the blogger attract more traffic.
Some parts of Atacama have not received rainfall for 500 years - but a sudden deluge of water upset the Desert's delicate biological balance
Spitzer Space Telescope could not spot Oumuamua, suggesting that it is actually pretty small
Greenland crater one of the 25 largest impact craters on Earth
This long-sought progenitor star was identified in an image captured by Hubble in 2007