So here's an unusual value-add for a mobile plan: if you sign up to a Vodafone Red Plan on a 12- or 24-month contract, you'll get a free Spotify Premium account for the duration of the contract.
Premium costs $12.99 a month, so that's not a bad extra. If you're an existing Red customer, you'll only get the deal if you recontract for another 12 or 24 months. It also won't be offered on month-to-month Red plans.
Vodafone announced a marketing partnership with Spotify last month, which led to some speculation that it might offer an unmetered deal for customers, so that music streaming wouldn't use your allowance. That hasn't happened: any Spotify music you listen to on your phone will still count against your data allocation.