Using bitcoin addresses as nodes does have some consequences that need to be carried in mind. There are some simple examples of behaviors that increase bitcoin addresses without actually increasing bitcoin adoption. For example, suppose a single user with 10 bitcoins in a single address sends that bitcoin to 10 addresses that he controls with one bitcoin each. This would not increase bitcoin adoption, but would increase the number of addresses. Similarly, using a mixing service that recycles bitcoin by sending it to new addresses would also not represent an increase in the usage of the network, but would technically increase the size of the network if it is measured in addresses.