Smartphone dating app Tinder launched a premium paid subscription version Monday, but drew criticism over a pricing system that charges older users more.

In the US, Tinder Plus users under 30 will pay $9.99 a month and older subscribers $19.99, according to Tinder. Prices will be as low as $2.99 in emerging markets.

Tech blog Engadget called the pricing scale “sleazy.”

A Tinder spokeswoman defended the policy, saying that the “price points were adopted very well by certain age demographics.”