Moves by states to collect sales taxes from retailers that use affiliate marketers, which direct Internet traffic to the retailers, are costing marketers heavily.

[...] last March, Gov. Pat Quinn of Illinois signed House Bill 3659, a so-called affiliate nexus tax that would require out-of-state retailers that advertise through Illinois-based Internet marketing “affiliates” like FatWallet to collect and remit Illinois sales tax.

[...] these laws have collateral damage. Caught in the crossfire of the nationwide fight —New York and other states have also passed nexus laws — are a large but rarely examined part of the Internet economy, affiliate marketers.