Amazon's accelerator program has existed for almost a year, and you've probably never heard of it. A new report could help explain why.

Amazon Accelerator gives sellers prominent placement on Amazon's website and individualized support from Amazon's marketing team. It also gives the tech giant the right to buy your brand for a predetermined price on just 60 days notice, according to the Wall Street Journal. Some who join the program are reportedly required to sign nondisclosure agreements, further explaining the secrecy.

The program quietly launched in late 2018 as part of Amazon's effort to bolster its private label sales. One Amazon Accelerator contract recently reviewed by the Journal granted Amazon the right "to acquire all of the right, title, and interest in and to each of the Exclusive Brands" for $10,000 per brand.

Under that contract, the vendor can sell the same products elsewhere under different brand names. After two years, Amazon can apparently source products for the brand elsewhere.

Some sellers are still signing up, embracing the short-term sales bumps while knowingly risking their long-term brand dividends. Unsurprisingly, other vendors balk at the prospect. "The additional exposure and marketing that Amazon has committed to put behind these brands is completely unfair to current sellers," an Amazon seller told the Journal. "It's a pseudo-partnership that's completely one-sided."