Ever heard about Google Adsense?
Google Adsense has a good reason to call itself "sense", because it
is targeting the advertisement basing on the hosting page content.
If your page is talking about foreign exchange, it then chooses the
FX ads to display on your page.
I found a truth: after I wrote a new post on my blog, the Adsense
trended to accumulate more points to my Adsense account. I guess it
is because that each new post causes Adsense to choose new ads to
display on my page. The new ads usually worth more.
By this mechanism, bloggers are encouraged to post more
often.