I will admit, I was a bit nervous about installing the plugin due to Solr core system required on our server, but the results are brilliant. I don’t know how it knows what you are looking for, but it does find it once fine tuned to you requirements. Even if you deliberately misspell words, the plugin delivers the results for the correct spelling of the search query. For serious on-line retailers I would say this is a must have. I cannot believe it is free, I would pay without hesitation. We have thousands of products all with very similar keywords, this helps our customers find what they need without any effort.