I've been monetizing data(email) using PPL offers for over 16 years. It's a highly scalable / sustainable business model and done right, it's very profitable.
I acquire data because I'm building assets that I then own and can market to the users over and over for low cost. Compared to what most marketers so which is to pay for traffic, that often just ends up generating a bunch of click and can't market additional offers to them. Or they use some free traffic strategy that often wasn't worth the time it took to implement. Where I basically own the traffic and can generate it on demand.
One note: I drive the traffic to PPL (pay per lead...lead generation) offers. This is because there is no credit card / purchase required. All a user has to do is fill out a form to complete an offer
/ generate a commission, so conversion rates are typically much higher than offers that require a sale to be made.
I favor offers that have a make, get or save money angle / benefit to them. As they have overall performed best for me and tend to have the greatest mass appeal (will be of interest to very large general audience). So the potential to generate high volume exists.
There are many good PPL offers that pay $20-$80 per lead that perform well. There are many other offers that pay more or less. However, the payout is not the most important factor. You also have to look at the conversion rate. You could have an offer that pays $8-$9 and if it is converting at 2X+ that of a $20 offer, then they will perform about the same. You could have an offer that pays $90-$100 and if it converts poorly, it may not even be worth running.
Some verticals I have done very well with are: insurance, education, debt, credit, mortgage, loans, homeowner offers, etc...
As for the data that I acquire...
I purchase fresh / targeted data in that I know what the users are interested in and that there is a PPL offer that matches their interest.
I generate real-time co-reg data that targets specific PPL offers.
I buy aged and domain targeted data, but this is a bit more complex and requires special tools / resources to do profitably.
Last, but not least. I get fresh/targeted rev-share data. Which is data that has $0 upfront cost and then I split the revenue generated with the list owners.
In case you are wondering, none of this has amything to do with spamming. All the data I get, all the users have provided permission to receive 3rd party messages, so it is completely can-spam compliant. Also, with co-reg, that data is very similar to opt-in, as the users are requesting more information directly from me.
I will say that 3rd party data will rarely be as respinsive as highly targeted opt-in lists that you develop on your own. So to compensate for this, you have to work with volume. Which is fine, as it is much faster and cheaper to acquire data, than building your own list.
The real key to making it work is to always be segmenting your opens / clickers and regularly remove the unresponsive users. This way you are then building smaller, but very responsive lists, so that later on you will be able to send less and make more with each mailing. Basically, you are converting the data from quantity to quality.
Essentially I am monetizing data using PPL offers, because they offer the path of least resistance to generating conversions (since they are free / nothing to buy) and converts the data into cash producing assets.
There is obviously a lot more that goes into it, but it really does work. Everyone that I know that is in the business and knows what they are doing, does 6-7 figures. While that is a huge range, much comes down to ones ability to scale and effectively manage the infrastructure that comes with scaling.
Something to think about.