High Scalability Building bigger, faster, more reliable websites.

One of the most popular and effective scalability strategies is to impose limits (GAE Quotas, Fotolog, Facebook) as a means of protecting a website against service destroying traffic spikes. Twitter will reportedly limit the number followers to 2,000 in order to thwart follow spam. This may also allow Twitter to make some bank by going freemium and charging for adding more followers.

Agree or disagree with Twitter's strategies, the more interesting aspect for me is how do you introduce new policies into an already established ecosystem?

One approach is the big bang. Introduce all changes at once and let everyone adjust. If users don't like it they can move on. The hope is, however, most users won't be impacted by the changes and that those who are will understand it's all for the greater good of their beloved service. Casualties are assumed, but the damage will probably be minor.

Now in Twitter's case the people with the most followers tend to be opinion leaders who shape much of the blognet echo chamber. Pissing these people off may not be your best bet.

What to do? Shegeeks.net makes a great proposal: Limit The New, Not The Old. The idea is to only impose the limits on new accounts, not the old. Old people are happy and new people understand what they are getting into.

The reason I like this suggestion so much is that it has deep historical roots, all the way back to the fall of the Roman republic and the rise of the empire due to the agrarian reforms laws passed in 133BC. In ancient Rome property and power, as they tend to do, became concentrated in the hands of a few wealthy land owners. Let's call them the nobility. The greatness that was Rome was founded on a agrarian society. People made modest livings on small farms. As power concentrated small farmers were kicked of the land and forced to move to the city. Slaves worked the land while citizens remained unemployed. And cities were no place to make a life. Civil strife broke out. Pliny said that "it was the large estates which destroyed Italy."

Om proposes one solution to the Twitter Problem is to limit followers to three square meals a day. The reasonable idea being that lower limits should mean fewer scaling problems. And as a kicker raising those limits is a good way to raise much needed revenue.

Scoble thinks users should consume without limit and will drive to another buffet if all-you-can-eat privileges are revoked. The reasonable idea being that if an internet service can't solve internet scale problems then there's not much use for it.

Dave says comp power users a top floor suite and shower them with free passes to the buffet. Let the good times roll! The reasonable idea being that power users help create popular restaurants, er, services in the first place and limiting them starves users and starved users won't come back.

So, should web services like Twitter be a buffet, a fixed eight course fine dining experience, a small plate restaurant, a family style joint, or a vending machine? Or something else entirely?

In a distant barely remembered past I actually worked at an all-you-can-eat buffet. The food was very good and most customers didn't over over indulge. If they did the place wouldn't stay in business long. But some customers did. They were called stackers.

Stackers were so named because a large stack of plates would pile up on their table throughout the meal. Stackers followed a power law distribution. Few customers at any one time were stackers, but their effect could be devastating. How devastating depended on their favorite foods...