Well there are a few things I look for (I will produce a bonus video about this topic and add it to the other bonus video tutorial) but basically I like to see sites like forums/niche sites/Q&A sites in the top 10 along with other things like sites that are not targeting exact keyword in title/meta, sites with low page authority and domain authority, sites that are less than 3 years old etc etc
"With Google giving over the home page to ads and their own properties for commercial keywords, the Long Tail keyword is more important than ever. If you have a website, you know that most of your traffic comes from keywords you never would have thought of. With Keyword Researcher, you can find them in advance and make sure that you're the one that snags this traffic. I use it for all of my e-commerce site planning."
Basically, Google shows the autocomplete suggestions whenever you start typing anything into Google search box. It is in Google's best interest to show the most relevant keywords in the autocomplete suggestions. Keywords that would help Google to retrieve the most relevant websites and help users find the most relevant content for their search query.
Long Tail Pro is a very useful piece of software for long tail keyword research. One of its best features is that you can carry out heavy analysis on the keywords of your choice, without being limited to only working with one or two at a time. It can provide you also with vast numbers of longtail keywords, or you can apply filters to find the precise keywords to fit your bill. And you can check your rankings at the same time!