There is much interest in studying the structure and evolution of the Internet at the Autonomous System (AS) level. However, limitations of public data sources in detecting settlement-free peering links meant that prior work focused almost exclusively on transit links. In this work, we explore the possibility of studying the full connectivity of a small set of ASes, which we call usable monitors. Usable monitors, while a subset of the ASes that provide BGP feeds to Routeviews/RIPE collectors, are better suited to an evolutionary study than other ASes. We propose CMON, an algorithm to classify the links of usable monitors as transit or non-transit. We classify usable monitors as transit providers (large and small), content producers, content consumers and education/research networks. We highlight key differences in the evolution of connectivity of usable monitors, and measure transitions between different relationships for the same pair of ASes.