RCN's acquisition binge is very helpful. Yes, they're all different, and they weren't just buying the customers, but no ISP consists of just customers. A look at how Wall Street values an ISP customer is also interesting. And then there's the cost anyone would have to pay to build a meaningful subscriber base from scratch, while incurring infrastructure and administrative growth costs. I also wouldn't use customer count as the defining metric, given the variations in pricing.
Revenue is a better measure.
And ultimately, when things settle down, profits will emerge as the true measure of worth.