Could Bitcoin dust spam be effectively combatted by actually including it in the block-chain? After reading this question I got interested in these mysterious spammers who sent satoshis randomly. For what I read, here's been plenty of discussion about this, mainly at Bitcoin talk (discussions here, here and here - in Spanish also here, 
here and here) but also somewhere else on the network (as in here).

I got sad when I saw I hadn't received such micro-payments, doubly sad when I read most of such transfers won't ever be included since most miner pools actively avoid collecting such "dust" - so spammer gets his message out for free, even though it may only last for a short while.

And I wondered - why not do include such dust, so that spammers are harmed economically and stop doing it? Plus, plenty of people would get tiny bits of money.

What would be the cons? Plus, if I've understood how Bitcoin operates correctly, spammers would end up paying much more in transaction fees than the amounts they actually send - which makes it doubly mysterious to me why not include them.
why not do include such dust, so that spammers are harmed economically
  and stop doing it?


I'm still not sure that would be enough to prevent this kind of spam activity. Even if these transactions were committed to the blockchain, 100,000,000 such broadcasts could be made from 1 BTC, that's a lot of reach for $700.