[quote name='Drahken']I think it's to make it so people don't order them then try to re-sell them or something, but there's really nothing to stop people from just sticking a new barcode on it or just putting a price sticker on the front.[/QUOTE]
It's actually so retailers cant buy them at a below wholesale rate from ADV and then turn around and return it to them through retail channels as unsold stock and get refunds. Especially when most of these sales are due to retailers returning more unsold stock than ADV knows what to do with.
For example, if retail prices for a standard DVD volume of a random anime series cost retail stores 12 dollars, and they sell it for $30, they would normally make $18 profit, and ADV would make those $12, minus expenses.
If that particular dishonest retailer decided to take advantage of these sales and buy that same DVD volume for 6$ (without drill holes), they could:
1) Sell the retail-bought stock for $30 (ADV gets $12)
2) Buy ADV sale items for below wholesale based on what was sold. (ADV gets $6)
3) Return the ADV sale items as "unsold retail stock", meaning they'd get their 12 bucks back. (ADV loses $12)
Essentially, unscrupulous retailers could make extra money on the side by taking advantage of sales meant to clear inventory. the drill holes mark it as a product that has been sold directly from them at an obscene discount.
This was an individual example, but you could imagine how bad it could be for business when you've got ADV selling Nadesico complete sets for 10 bucks during sales, and then buyers who deal in bulk.
Anyway, long story short, drill holes = cheap anime. I remember when I was younger, my local comic shop would sell comics that were normally 1.50-4.95 for 10 cents, just to clear out space. the only thing was we had to deal with markers crossing through the UPC. same thing. If you don't like it, dont buy it.