There are a few reasons why.
First, in the spirit of transparency, payment processing is expensive. We want to give you the most value back for your data while letting you cash out frequently enough.
Second, we can create better internal economies at the $40 threshold. Over time, your points will become exponentially more valuable so that you can put them towards higher-valued coupons and rewards. This means more value for your data and more bang for your buck!
NOTE: Your connections must be active for at least 30 days in order to cash out and that points expire after six months on a rolling day basis.