That works out to getting two months for free, which makes it a no-brainer if you already subscribe to that tier of Spotify and need to renew your subscription. There aren’t really any caveats; the price is available to new or existing Premium subscribers, except for those already on a family plan. And once the 12 months are up, your plan will revert back to whatever the current monthly rate is at that time, which is something to be aware of.
The new discounted price also means that Spotify is, at least temporarily, just as cheap as Apple Music, which added a $99 / year option earlier this year. That may help if you’re still choosing a streaming service.