My VA built a 1,900 record mail list. A third of it was garbage.
Construction is my background, marketing is not, so when I decided to send mail on absentee owners in two counties I hired a VA through an agency at $8.50/hr to build the list. Ten hours a week for six weeks. Total labor about $510, which felt like nothing.
Here's what happened. I gave her the criteria verbally on a call, she pulled from the county assessor sites and a skip trace tool I paid for, and six weeks later I had a spreadsheet with 1,914 rows. Looked great. I sent all of it, two touches, at about $0.78 all in per piece. So roughly $2,980 in postage and print.
The returns started coming back and I counted 412 pieces undeliverable. When I actually sat down with the file I found something like 210 duplicate owners where the same person owned three parcels and got three letters, a batch of rows where the mailing address was the property address on a vacant house, and about 60 rows in a county I never asked for because she'd misheard the name on the call.
Call it a third of my spend on mail that was never going to land. Then I spent two weekends cleaning the file myself, which was the real cost, because I do that work at night after job sites.
What I'd do differently. Ask for the first 100 rows before she builds 1,900, and hand-check all 100 myself. Write the criteria in a document and have her repeat it back in writing. Dedupe by owner name and mailing address before printing, not after the returns show up. None of that is her failure, it's mine for buying a finished product I never inspected in progress.