Here is, perhaps, a more callous approach to all the discussion going on about where to post info on rarities:
I'll preface my remarks by saying that COBIRDS google group is my personal preference for posting info and finding info. There is, of course, also the COBIRDS facebook page. I'm also on the Colorado Rare Bird Alert facebook page. I also periodically read and post on birdforum dot net (subgroup forums, subgroup your local patch, subgroup Colorado). And of course, I get a lot of info about where to find birds on ebird.
No one is required to update all, or any, of those databases. We could see a rarity and just mail a letter to the CBRC the following month, but we all benefit from fast info, and people are really good about getting info out incredibly quickly. This info quickly spreads from one site to another.
So, what's my advice? If you really expect that every report will reach you personally, and instantly? JOIN THEM ALL. THEY'RE ALL FREE. Bringing others' preference of internet medium in line with one's own, in any context, is pointless.
Dave Cameron
Denver