"I would consider that low value content"
"I would consider that low value content"
It's not high value from a monetary perspective either. It's low value, high volume. And anything low-value and untargetted enough IS spam.
I would quantify value of an informational chunk by viewing it as a signal and measuring the degree of data compression present. For example, a Groupon listing has extremely high value as it compresses all of the economic data in an entire city to a single very best coupon at a rate of one per day.
The only difference between spam, ads, and content is the probability that the degree of compression or informational value they offer is greater than the attentional resources required to absorb it. The threshold values between categories vary person to person of course.