Solutions and alternatives for new user names
Early in its existence, Twitter noticed that new users were getting to the username selection page, typing in a few ideas, then, unable to come up with a username, abandoning their signup attempt when they couldn't get their desired username. A simple change was made to fix this: switching the order of the fields. This way, they could use information like a new user’s email address to proactively suggest username ideas.
Gmail's signup flow also offers suggested names based on the user's real name, and Reddit gives newly signed-up users an automatically generated abstract name. All of this is happening in part because of a shortage of good original usernames, leading to a growth in search volume for terms related to username ideas.
The new tools
It's always possible to create a username by typing random characters, or by adding lots of numbers to a real name, but these accounts are seen as low-status—a Twitter handle like “@jim8132048250987” just looks like it belongs to a bot, even though it could just as easily belong to someone named Jim who is impatient to start using the service.
Creating username generator tools that live outside of a site is tricky because the usernames may be taken, but it also creates an interesting advertising opportunity: someone who is creating a username is a potential user of a service, but not an active one, so they may be in the market for an alternative, and the username selection process is a prime time to market one to them. Much like Shopify has made it easier to find a name for a business in order to kickstart business growth, sites that make it easy to choose a username can acquire more users.