Call it a history, an event log, a lifelog, microblogging, or whatever you like: The practice of telling your social circle what you’re up to appeals to our always-on OCD, our need to interact, and our love of bumper-sticker succinctness. Sometimes it’s sublime; other times pedantic; occasionally awkward. But it’s here to stay, and represents another model of communications.

Twitter is to blogging as Instant Messages are to e-mail. And it’s on the rise.

Can it keep growing?

On the one hand, microblogging platforms enjoy strong network effects: More people means a more useful network. You can find and follow more people, and add more applications. Twitter’s acquisition of search tool Summize is one example, but there are many other apps out there. So in theory, it should grow and get better.

On the other hand, there’s a downside: The bigger you are, the harder you fall. and while Twitter outages get the headlines, it’s the slow contagion of spammers and linkbait that may prove the undoing of microblogs.

On a microblog, a few prolific, heavily followed posters, the Scobles and Arringtons of the world, generate a disproportionate amount of traffic (check out some great visualizations of this.) Often, they’re just pointing to new articles they’ve written or found: It’s a recommendation engine, the subjective cousin to Google’s relevance algorithms.

Twitter has always been about directing attention, and by now, the cast of Twitter actors is in the millions. Twitter really took off when people used it to follow their favorite stars and find out where they were playing. So much so, in fact, that I think Twitter is an API for herding humans.

Cue the abuse. Here’s how it works:

With a microblog, anyone can follow you. And by default, you’re told about it. Vanity takes hold: You want to see who’s interested in you, and you look at them, possibly to reciprocate. This happens on blogs, too, and anyone who writes online reads the comments they get.

I get notified when someone follows me. And much as I’d like to believe I’m that interesting, it’s pretty clear that the followers aren’t in it for conversation. An increasing number of my followers’ tags say things like, “I’m trying to reach 1,000 followers for a school project.” Go to their Twitter profiles, and every post links to a get-rich-quick scheme, a stock, or something similar.

Twitter spam could cost, too, if carriers charge for unsolicited inbound messages and I were vain dumb enough to want to know when someone followed me.

Scaling microblogs is the obvious problem: If I send ten messages a day to 50,000 people, that’s a lot of traffic. It’s a hard problem. As Werner Vogels told me a few weeks ago, “all the small guys are telling them how to fix it, and all the big guys are staying quiet.”

But there’s a second, softer scaling problem that rots microblogging from the inside. As they become popular, microblogging sites need to scale community standards, following, blocking abusive users, and reducing “follow spam” in a scaleable way. Otherwise, we’ll see churn from older to newer services as a constant part of the world.

In other words, the microblogging meme is here to stay, but the platform’s still being worked out.