In reply to Andreas Nurbo.

Growth isn't a goal, it's a result of having the right technology, product, design, messaging, price, awareness, and flows. WordPress has done great here in the past by getting the right mix of those. To see whether you're doing a good job or not, it's good to measure things like number of sites or market share, but if any one of those seven elements isn't working it will slow the rest down: An amazing product no one knows about will wither on the vine. A well-marketing broken product will die too.