Not sure if ML was the original doing the reverse, but they were one of the first I know of. Basically for people that are stacked out and near the tail end of the advances the funder doing a reverse will give weekly disbursements into the chk acct to help float the merchant a little bit while they are struggling. It usually helped reduce the obligations by about 20-30% ish depending on the specific. Ex merchant is paying $500/day ($2500/wk) reverse funder will wire 2500 per week and will pull $350 day to try and give the merchant a little breathing room.