This week brought us dueling product announcements from Google and Microsoft that, naturally, got a lot of attention from media and bloggers. But as I was reading about Microsoft’s new search engine, Bing, and Google’s upcoming Wave communication tool, I noticed something interesting about how the companies are trying to capitalize on crush of media attention and Web traffic.

- Google’s Wave homepage features a prominent blue button that says, “Let me know when it’s ready,” which takes users to a quick survey and email sign-up form to be sent future updates about the product.

It’s a smart tactic: Product-launch alert campaigns are a great way to capture opt-ins, and those messages tend to generate strong open and clickthrough rates.

- Microsoft’s Bing homepage, on the other hand, doesn’t feature an email sign-up form (as far as I could see). Instead, it appears the Microsoft team is using social media to make connections with interested visitors.

The Bing site features a link to a Bing Facebook group, and invites visitors to follow Bing on Twitter.

I haven’t seen data or done a case study yet on using social media to keep potential customers in the loop about product announcements. I’d be very interested to see how it compares to email in generating interest and activity after launch.

But in both cases, Google and Microsoft are being smart about weaving an engagement strategy into a big publicity push. Whether you’re using email, Twitter or another channel, you can make a direct connection with your audience that turns a sudden, transitory wave of interest in your company or products into the first step of a long-term relationship.