From Free to Paid: Public Attitude Change and Mechanism Evidence around Doubao's Charging Announcement

As generative AI moves from free access to paid subscription, how charging shapes public attitude bears on platform commercialization. Taking Doubao's monthly subscription as the setting, this paper builds a dual-path framework of “product experience - price perception”. Using the announcement date (May 4, 2026) as the breakpoint, we collect public Weibo discussions from 30 days before to 30 days after it (2-day periods; the 14 days on each side form the main window), measure attitude with aspect-based sentiment analysis, and test changes at the breakpoint by regression discontinuity in time. Negative evaluation is robust in direction for Payment Willingness (τ = +0.751, p < 0.001) and Corporate Brand (τ = +0.647, p = 0.011), but rests on only 27 and 7 pre-breakpoint texts, so the magnitudes are read as direction only. The negative share for Price & Charging shows no significant increase (τ = -0.161, p = 0.123), so the price-fairness path is not supported. The difference between the two aspect jumps is -0.532 (clustered SE 0.437, p = 0.245), opposite to expectation and underpowered given the small pre-breakpoint sample; we report only that no larger negative change was found for the price path than for the feature path. The overall negative share rises by 0.317 (p = 0.041) but depends on a pre-breakpoint period with 3 relevant texts and falls to 0.043 (p = 0.517) without it, so it is not robustly supported. The conclusions are limited to a marked change in attitude, with no persistent shift and no strict causal claim.