Blockchain.info is the most commonly used online bitcoin wallet. As shown by the graph below, today more than 10,899,000 are using blockchain.info's bitcoin wallet. The number of users of blockchain.info wallets is a reliable indicator of the adoption and usage of bitcoin, especially that the wallet is secure, well reputable and doesn't store the private keys of your bitcoins on the servers of the website.
The number of users has been rising since the launch of the service, yet a logarithmic boost in the rate rise was witnessed when bitcoin price exceeded $1000 early in 2014 and received mass coverage by mainstream media. For many, using a bitcoin desktop wallet is a hard task and this is when blockchain.info's wallet becomes handy. As bitcoin price is approaching the $1000 mark again, the number of online wallet users is expected to exhibit another boost in its rate of rise.