There isn't enough data to calculate numbers as soon as the visits come in. If I pay $3/month and visit your site, the amount you get depends on how many other

There isn't enough data to calculate numbers as soon as the visits come in. If I pay $3/month and visit your site, the amount you get depends on how many other site visits I accumulate during the month. If I visit 2 sites, you get $1.50. If I visit 20 sites, you get $0.15. You also need to store browsing history to avoid scammers redirecting other users donations. This happens on similar platforms like Spotify. You register for Flattr and just run a script to constantly visit your site. With aggregated statistics, this shifts a bit of everyone's donations to you and can be extremely lucrative. With session history, you just get your own donation back, minus fees.