As far as I'm concerned spamming is when someone joins a site merely to promote goods for sale or another website. If, for example, someone starts posting what appear to be 'harmless' posts but they have a link to a sales website either in their signature or as their homepage, I would consider that spamming.
Note - this is not the same as a well established member posting a link to a site that they own that sells things - for example Mad Collector and chillicamper.
We also tolerate people posting to advertise Discworld related things such as plays etc.
I do not consider posting a smiley as spam. Sometimes a smiley says exactly what you want to say. For example; you don't need to write "that's very funny and I'm laughing out loud when you can just post this -->
As Q says there is commercial spam which we don't tolerate and then there are trolls - thankfully we've had very few of those here.
Look, you've got it all wrong! You don't NEED to follow ME, You don't NEED to follow ANYBODY! You've got to think for your selves! You're ALL individuals!
Yes! We're all individuals!