How can big dealers charge less for products? One reason why might be because they get paid faster–not because of their size, but because they bill electronically.

Billtrust, the Jamesburg, N.J.-based provider of outsourced billing services whose customers include six of the 10 biggest companies on the ProSales 100, says the percentage of bills sent electronically by its building supply customers has jumped from 23.4% in 2008's first quarter to 35.2% as of the third quarter of 2011.

Presenting bills electronically means the invoice arrives faster in the customer's in-box, particularly if you mail from your headquarters to a big geographic area, Billtrust's Mitch Rose points out. When one combines electronic invoicing with a system that lets customers pay the bill online, accounts receivable days outstanding can go down an average of three to 10 days, he says.

"If somebody typically pays by check and it's due on the 30th, they'll drop it off on the 28th or 29th," Rose says. "Then you deal with mail time and paper check and processing it into the bank account. When you pay online, that mail time goes away. The faster you get the bill out, the faster you're paid."