According to Caroline McCarthy at the CNET blog, the growth is attributed to the announcement of OpenSocial. Admitedly, this is Plaxo’s data, not her conlusion. Her blog post is worth reading. (Dear Caroline, don’t worry about my readers getting the wrong message here, the truth is, no one reads this blog ;)).
However, I have an alternative reason for Plaxo’s growth. It’s because they decided to open the spam machines out again. I swear, this seems to be the same time frame that I received about a gazillion plaxo invites. Like this one:
Just for the record, I like what Plaxo can do, and think it’s tre-cool. But just when they were getting over the brand and perception that they were a lean, mean, spamming machine, they opened it up again and became the topic of (negative) discussion. Oops.