As my normal job, I work at a national payroll bureau. I used to add content to the work website, as and when time allowed, and I even set up the companies twitter account in my own time after realising that no-one else had done it.
A year or so after doing that, I was asked to had over control of everything to someone else in the company, so I no longer have any involvement with its online presence.
UKPayrollAdvice is a site where I can give advice about payroll, but can do it in a much less corporate way. It has friendly, occasionally jokey advice, but remains factual.
Within a few months UKPayrollAdvice’s Twitter account was already more popular than the one I had to renounce control of. Which was nice.