Some are free some go for a price that even scammers/spammers can afford.
Voting Registrar
Drivers License
Cole Information [lots of demographics, address, income, race, etc, may not have text/email and VERY expensive]
Black market email list [unverified cheap, verified have a higher price]
...many more
takes little time to filter out no email and/or phone numbers that are not land line only [readily available as area code - prefix - ####]
I enjoyed my job doing addressing, like playing Sherlock Holmes, for 20 years before retiring in 2015 where doing the above and mapping the results took a lot of my time.
For those that don't know mapping is great.
Take law enforcement records for say "domestic violence", more in economically depressed areas, less in affluent areas.
You have some type of area to work with say political areas, city council / county government / etc.
Now shade them white to the maximum count in "red".
That is what law enforcement needs to target, which means more money for man power.
If you take that to the "council" it goes in a trash can because red is a "deficit" so no more for you.
So just change the color to "green".
Who ever owns the bright green area will be on the hot seat, crap if I don't get this fixed I won't get reelected. Here's some money.
This is not lying it is just knowing and targeting your audience.
Those colors are burned in their brain, but spreadsheets and other "data" print outs goes in the closest trash can.
Data Analyst is a great paying job. Can even be done remotely in the CV-19 era.