That's a bold question to ask the world, but I don't think it's a question about harm. It's a question about purpose.
From our vantage point, quite a few companies equate word of mouth marketing to the BzzAgent approach, which retrofits the classic model of advertising: Send information to a pre-determined demographic group of prospects and hope they'll act on it. In this case, the campaign "information" from BzzAgent is most often a product. After sampling, the desired action is buzz.
A few weeks or months later, everyone moves on. Some buzz has spread. That's the purpose. Is that approach harmful to the word of mouth industry? It depends, of course, on what you believe the industry should hold high, how it should behave, and who it represents.
If anything, the buzz surrounding BzzAgent has coaxed the marketing groups of some big companies to consider word of mouth alongside their traditional menus of coupons, inserts, TV ads, co-ops, etc. Measured against the longstanding, one-way nature of most traditional marketing programs, that's progress.
But BzzAgent symbolizes something else: a schism in the nascent word of mouth "industry." On one side are advocates for outsourced buzz directed at prospects. Let's call them the "new traditionalists." On the other side are relative purists who believe existing advocates are best-suited to create organic word of mouth because brands create remarkable products and service. All of which adds up to greater loyalty. Let's call them the "WOM progressives."
New Traditionalists are comfortable with BzzAgent because it speaks their media-steeped language. (BzzAgent calls word of mouth a "media channel.") Since scores of companies haven't invested the time or resources to build their own customer communities or networks, BzzAgent provides ready access to a network. Many ad agencies see the BzzAgent model as complimentary to the traditional marketing mix.
The WOM Progressives don't care for the New Traditionalist model because it represents a marketing shortcut. They should build their own networks of loyalty. Furthermore, an underlying fear of the WOM Progressives is that the New Traditionalists will eventually pollute the "media channel," i.e., society, with undercover agents who secretly manipulate moms and kids. Of course, a fair number of lower-profile "guerilla" agencies already do this. BzzAgent encourages its agents to disclose their affiliation.
Which leads us back to the beginning and purpose: short-term campaigns vs. longer-term customer relationships. Some companies may take years to develop their own networks, if ever. Perhaps a split in the WOM industry one day between the New Traditionalists and the WOM Progressives is inevitable.