Currently there are at least 60 ISPs serving the San Diego county area. There are LOTS of packets from "home" to "office" that make a round-trip via MAE-West. Some people have decided that this is silly. Even if it is "cost-effective", it *squanders* bandwidth at MAE-West that could best be used for other traffic.
This is true in almost every major metro area. I help found an exchange point in St. Louis. Not MAE-East levels of traffic, the exchange peak at about 2.4 Mbps of traffic (more than a T1's worth). http://www.stlouix.net/ But that's 2.4Mbps of traffic that didn't travel 2,000 miles to get across town. Of course, not every local ISP participates. The state subsidized education network doesn't connect, nor do some the dialup ISPs. But it gets a reasonable level of support from several of the larger area providers. But exchange points are one of those weird creatures. If I'm paying a big expensive backbone, why would I get anything from a local exchange point? And of course, the ever popular "What's the catch?" Since local exchange points are generally run on a non-profit basis, that means there isn't a large marketing organization, or a huge gaggle of salespeople trying to sell it. If you like, we can call it a "managed connection" and charge you $1,000/month. But that seems steep for essentially a port on a catalyst switch. But we've found once an ISP connects, they generally keep it. -- Sean Donelan, Data Research Associates, Inc, St. Louis, MO Affiliation given for identification not representation