Hello @crypto.piotr ,
Nowdays people spend Millions of $ on a billboard at newyork time square Where there is a limited audience to see the ad. On comparison a billboard with an digital audience watching the Superbowl I think of it as insane value ...heres my evaluation.
Lets keep it in therms of investment
✓Good investment
It would be an good investment it got a lot of new customers ( where now coinbase could earn millions from trading fee itself). This would be a big win ,new customers + more people are aware of coinbase now.
✓ Bad investment
This means it was failure and they could not retrive what they invested .But it's actually a success in disguise because most of crypto in my perspective works on hype And coinbase probably got a lot of attraction . As you mentioned the website crashed due to a rapid increase in traffic which is possible only if the developers weren't expecting such an overload on the servers, Which means it blew way hugher than what they expected .
These are my thoughts/theory on the above topic :^)