Mattermark is something of little relevance to me but how good is the data? They recently produced a list of the fastest growing startups in my local community and the results were pretty odd. Companies with huge measurable growth beaten by, literally, new starts just a few months old with no revenue and few customers.
Granted I don't know what yard stick they used to come up with the list but to me on the ground in the community the list seemed way off and widely ridiculed.