Rob Powell at Telecom Ramblings has his lit building chart updated. Top 5 most lit buildings is TWT, L3, Optimum Lightpath, FiberTech and XO at 3000.

So L3 tried to sell mainly on-net via the channel. They would light any building within 400 feet of a fiber route. That strategy did not work well. Here's one that would:

Take your lit building list and populate it with all the tenants in those buildings. From Harte-Hankes acquire the lead info like contact name, SIC code, number of computers, etc. Now hand that off as a lead list to your channel partners to see what develops.

You could also do that with buildings to be lit.

FYI, a lit building means that not only does the CLEC have fiber into the building, there is at least a pair of fiber strands lit up with optics. Hence, lit building. The first customer costs the most, the 3rd customer in a lit building is all gravy.