You're right about this; I should have noted this initially. I used "Welcome Wagon" because it connotes something that although well-meaning, is contrived. I find these mass greetings, marketings, et. al. disingenuous in the same vein as phishing.
Put up a blog post or start a discussion; I've been part of many online recruiting communities where these mass events practically take over the postings and responses to questions become marketing opportunities.
Doug Franklin of ContractRecruiterJobs on Yahoo groups posted this. Very nice.