Ceteris paribus, the greater the supply the cheaper the cost, which can sometimes translate to a lesser value. Blog posts are easy to produce, and can thus be of less value. Facebook status updates and Twitter posts even more so; how many of those do you remember reading from yesterday? Or the last hour?
I don’t subscribe to the labor theory of value, but if something is difficult to produce there is likely to be in short supply and thus the good would be more valuable. Though with some things its value is barely elastic no matter what its supply, simply because people don’t value it at all no matter the level of supply.
Thomas Paine’s Common Sense pamphlet is still being printed and read over 200 years later. This people are willing to pay (though not a lot) of money to purchase it. It has something in it that outlasted the pamphlet medium.
The goal is the same today as it was for war pamphleteers in colonial America: will you make something now that people will value no matter form it is in?