A Web service's adoption cycle certainly has multiple stages - from its initial development, to seeding with bleeding-edge adopters and test accounts, gaining word of mouth and referrals, leading to more early adopters and tech aficionados, before being poked at by more mainstream folks, and eventually, technology laggards.
A key element of graduating a service to the mainstream is a positive review from an objective, trusted, third party. Once the trusted third party gives the service their blessing, it's a sign the masses can sign up and expect it to work flawlessly.
In a great post this morning, where I happen to be mentioned a few times, Mark Hopkins of Mashable admits to both wanting to be in the early adopter role, and find services first, but also, needing to play the more cautious role of harsh reviewer, a role shared by blogging compatriot Steven Hodson. Where I may express excitement about potential, they can express caution or annoyance if a bug gets in the way.
In marked contrast, when I find a bug in one of these new services, I typically have made a screenshot and e-mailed it to the developers... and I'm currently in the QA phase for a few services we'll be talking about in the next coming weeks, playing that role before it's time for their unveiling.
So... depending on where you live in the adoption cycle, you might love a new service's potential, or you may hate that it doesn't do everything you want immediately. But we know our role, and when Mark thinks these services have passed the threshold for a Mashable endorsement, that will be an exciting day for entrepreneurs who keep tweaking their code.
See: The Early Adopter vs. The Harsh Reviewer