You know the way all government sites are meant to be merging into Directgov... does that or doesn't that cover externally located subdomains of direct.gov.uk? I did a quick bit of Google research and uncovered the following non-authoritative list:
- ema.direct.gov.uk (plus moneytolearn.direct.gov.uk and yp.direct.gov.uk)
- studentfinanceloangrantcalculator.direct.gov.uk
- countdowntouni.direct.gov.uk (plus unimoney.direct.gov.uk and bursarymap.direct.gov.uk)
- taxcredits.direct.gov.uk
- nextstep.direct.gov.uk
- actonco2.direct.gov.uk
- jobseeker.direct.gov.uk
- local.direct.gov.uk
- nuclearpower2007.direct.gov.uk
- togetherwecan.direct.gov.uk
- volunteering.direct.gov.uk
- bluebadge.direct.gov.uk
- sharp.direct.gov.uk
- kids.direct.gov.uk
Several (although not not all) of these sites clearly required functionality which the Directgov platform couldn't offer: database integration, mapping, etc. And that's where Directgov's problem will come. If you're going to bring everyone on board, you need to be offering adequate functionality - or at least, access to adequate external functionality - to meet everyone's perceived needs. As it stands, we risk ending up with a proliferation of subdomains.
There are plenty of good reasons why sub-domains might exist. For instance for campaigns or specific audiences. Don't think they necessarily exist because of the underlying functionality of the platform, and it doesn't contradict the convergence / rationalisation ethos as far as I can see.
As someone who has been involved in migrating a stand-alone site into Directgov I believe that while some subdomains may exist to aid campaign promotion I would argue most are actually "white-labelled" externally hosted pages that simply can't be replicated on the Directgov infrastructure at present. Of course with £30m coming Directgov's way this year it may well only be a matter of time if the will or expertise remains post-migration.
I'll leave the benefits/efficiencies (or lack thereof) for others to discuss...