Google Business offering $80 Ad credits on a spend of $45

I set up a business listing with "Google Business", which is part of Google. When you register, they send you a postcard (!) with a verification code - its arrived for me about 30 days later.
When I verified, they pop up an offer of $80 in ad credit on a spend of $45. It's actually in euros, so I don't know if those are the exact dollar amounts.
There's a 2 month time limit on the offer.