Log-rolling is mutual back-scratching among writers, critics, or poets, where each gives the other public praise, favorable reviews, or support in return for similar treatment. The practice is usually seen as biased and self-serving, especially when honest criticism is replaced by friendly promotion.
In literary circles, it can weaken trust in reviews because the praise may reflect an alliance rather than a fair judgment of the work.
Example
The reviews began to sound like a chorus of favors:
Your sonnet is luminous, mine is too,
and we will each call the other brilliant
so the books can rise together.