The most profitable vertical that I am directly engaged in involves lawyers.
The great thing about legal lead generation sites is that there are many specialized areas of law practice.
On the federal level, there are many immigration lawyers, for instance, who would be interested in leads.
And this is just the tip of the iceberg.
Since federal law, which covers all of the United States, has many different practice areas, there are many types of lawyers you could deal with, which means more opportunities.
The downside to this, though, is that you have to create solid legal content that not only delivers clear value to the reader but doesn't get your client or your lead generation website in trouble because this is legal material.
And we all know that lawyers can be very, very picky and sensitive when it comes to legal topics and the law.