We and others have documented plenty of cases where papers get retracted because authors manipulate citations to boost their impact factor.
Sometimes, journal publishers pressure authors to cite papers within the journal to artificially inflate its impact factor. Since this is highly discouraged – COPE has extensive commentary on the problem – it usually happens behind closed doors.
Since we’re all about transparency, we were delighted to discover that the Thammasat International Journal of Science and Technology, a publication out of Thammasat University in Thailand, lists the policy up front:
Please kindly give some citations related to your written article from any articles published in TIJSAT in order that the TIJSAT’s impact factor can be raised to a higher level.
Here’s a screenshot, in case the journal gets cold feet (click for larger version):