ALDI pop up in a link?

I clicked onto a link this morning, about Esther Rantzen and estrangement. I think, as I didn't get very far.
Then, up popped an ALDI ad, saying that they had vouchers to give away!!
As I didn't see a way of getting rid of said pop up, I answered 3 questions, and was told I had won a voucher. Naive?
Anyway, I then couldn't open the next bit, as my IPad deemed the site was not secure.
Are these pop ups for real, or just another scam?
Anyone else had them?