Below are several charts tracking the Digital Currency ecosystem. Links to embeddable images (of multiple sizes) are available for each chart. All chart images are free to use and distribute for any purpose.
Chart 1: Number of Merchants Accepting Bitcoin: 2009-2014
This chart shows the number of merchants accepting bitcoin for goods or services. These data are compiled from public statements made by the two leading Bitcoin merchant service providers: Coinbase and Bitpay. This chart does not include merchants who accept bitcoin via other means.
Chart 2: Online Bitcoin Community Growth: 2009-2014
This chart attempts to capture general community growth by tracking the number of bitcointalk.org forum users and the number of users subscribed to the Bitcoin subreddit by year. These figures are are somewhat rough, as some interpolation had to be done on publicly available data, but nevertheless, it gives an accurate portrayal of the growth dynamics of online Bitcoin communities over the past few years.
Chart 3: Venture Capital Investment in Digital Currency Companies: 2010-2014
This chart captures venture-capital deals in the Digital Currency space. Data were obtained from cbinsights.com.
Chart 4: Number of Known Web-Wallets: 2011-2014
This chart shows the total number of known web-wallets. These data were compiled from figures publicly released by blockchain.info and Coinbase, the two most popular Bitcoin web-wallet services as of Q4 2014.