Peter, I think the problem is that business have been created, received funding and developed over the past year, with the full knowledge of Twitter, and this just undercuts & destroys them.
I think people can understand the rationale (and the desire for Twitter to eliminate competition) but this is a policy decision that should have been made over a year ago. Twitter should have included this in an earlier terms of service instead of giving an implicit "okay" to services like Sponsored Tweets which has turned into a successful company. It also seems disingenuous that the blog post says that a "guiding principle" of Twitter is that "We don't seek to control what users tweet. And users own their own tweets." and allow adult-oriented content and photos but for some reason, users can't Tweet ads. That sounds like control of content to me. Liz
