One thing to watch is the usage of mobile devices (thinking phones for this point) as the only/main internet access device for young adults.
Too many people think about mobile actually being out and about, it's much more than that. Many of us will shudder to think that some (read very many) people are happy to use such limited (in size rather than capability) devices to do hours of online stuff every day. How do you cater for an audience you don't fully understand?
It's time to segment mobile into a few different usage scenarios with at least:
Small Screen (people using mobile like desktop, who use a desktop as a main device)
Primary Screen (the device is the main device, hence desktop familiarity lower)
Mobile Screen (actually on the move or out of the house)
Simplified Screen (Think apps and simplified mobile sites, possibly by choice the user opts for simplicity where available)
Medium Screen (tablets, no space issues but not a desktop environment)
Plus, you probably want to consider offline usage too - it's still an issue, especially if an app is needed by a mobile workforce.