It was only a month and a half ago that the service hit 4 million users, just in time to announce their big $9 million Series A round of funding.
And earlier this summer, CEO Dick Costolo spoke of a "live events" tool which would let users scroll back in time to see spikes in conversations around some sort of planned event or breaking news.
Some firms delete accounts after inactivity; others refuse to allow renewals to keep the data alive; others won't allow any changes, and leave a user's data frozen in time, to the distress of those left behind.
For instance, one commercial depicts how a user can "jump backward and forward in time to capture the perfect shot" of a child who is hard to photograph.
But for the larger companies, such as Apple, Facebook and Microsoft, it is not as common to see executives directly involved with the project working with users in real time to answer questions and resolve issues.
All of these actions are handled via an online dashboard, which also allows developers to message users in real-time to head off bad App Store reviews.
The PLM system manages many kinds of documents, like the project description and scientific target, the sub-system requirement, design reports and critical data; and distributes them to corresponding users in time.
This takes constant user time of 0.9 user seconds to match 1000 sequences to reference panels up to size 10 000, but for 50 000 reference sequences the size of the stored u, v and d arrays (which were not compressed in this implementation) became larger than the available memory, resulting in an increase in system time from 0.2 to 15 s, and a smaller increase in user time to 1.7 s.
It will then continue to check back in with users over time, to see how those tastes may have evolved.
