Today a subscriber who had been paying monthly converted to an annual plan, our first one, and also upgraded plan tiers at the same time. It was a nice vote of confidence for WP Lookout's value and it was also a relief that the subscription conversion worked. :) The user's motivation for converting was to increase the quantity of themes/plugins they could track, so it's also good to know that this can be a driving factor (at least for a sample size of one).