Why will the visitors of your site care about Acquia Search? For a while now, I have Acquia Search installed on my personal site. To understand what Acquia Search can do for your site, have a look at what it has done for my site. While I have a very simple Drupal site, you should be able to experience some of the benefits of Acquia Search.
For example, search for "Drupal" on my site (use the search widget in the sidebar) and you can see the facets that allow you to filter the results by topic, location and industry. Using these facets, it should be pretty easy to find all the Fortune 500 Drupal sites that I blogged about in 2009, for example. Facets make search faster, making it very easy for your visitor to drill into results and to find what they are looking for.
Acquia Search makes search easier because it is built on the principles of progressive disclosure. Instead of showing the visitor an initial page with lots of complicated options (see Drupal's advanced search options that almost no one uses), the facets are only shown after the initial search query. Plus, and this is really cool, facets are dynamically generated based on the search keywords. As such, they are relevant to what you're searching for.
Acquia Search provides a more powerful search because it is based on the renowned open source Lucene and Solr technologies from the Apache project. Not only do they sport better search algorithms, advanced content normalization, and a "did you mean?" feature, they also come with other great features such as word stemming, document search, range queries and more.
My favorite feature of Acquia Search, at least for use on this blog, is the "more like this" feature — on node pages you can ask Acquia Search to suggest related content. I have been using it on my site for a while (see the block in the sidebar), and it has helped to keep visitors on my site longer. I occasionally find myself getting side-tracked by the "related links" — it is a great way to re-discover old posts.
Last but not least, our new service makes for better performance. We performed tests of searches on a Drupal site with over 10,000 nodes of content using a 3.2Ghz dual core server with 1.7 GB of RAM. With Acquia Search results were displayed in less than half a second, whereas the same results served from Drupal's built-in search took anywhere from 1.5 to 7.7 seconds. On the web, faster is better.
That makes for a lot of good reasons why the visitors of your site might care about Acquia Search. Tomorrow, I plan to write a more technical blog post about how Acquia Search works, how we made it that fast, and why it matters to site administrators (instead of site visitors). In the mean time, I recommend that you play around with the search feature on my site or that you sign up for a trial subscription. Have fun!