By using a collaborative filtering method, we can identify keywords that are closely related to "opt-in". Of all the web sites that target "opt-in", these are the most commonly targeted keywords by this same group of web sites, sorted by the highest number of web site matches.
The root keyword phrase "opt-in" also exists in these keywords. Drill down to see who is targeting long-tail variations off of "opt-in".
The keyword phrase "opt-in" can be broken down into these keyword pieces. Find out who is targeted short-tail variations off of "opt-in".