## 6 Simulation Results
### Sensitivity Tests
#### 6.2.2 Varying Strategy Indexes among Different Proportions of PIRs  
1. Varying the index related to value output  
* Varying service quality  
Figure 5 shows the sensitivity of the market penetration at each step to varying service quality from 0.5 to 0.9 with different proportions of PIRs. An increase in service quality contributes to the increase in market penetration, while the effect of enhancing service quality is more effective in the target audience with lower proportions of PIRs. To clearly analyze the moderating roles of the proportions of PIRs in the positive relationship between service quality and final market penetration (MP), we conducted an additional regression test. As indicated by Equation (7), the interactions of the proportion of PIRs with service quality have a significant negative impact on final market penetration; that is, the lower \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Equation**} & \multicolumn{5}{c}{**Model Summary**} & \multicolumn{5}{c}{**Parameter Estimates**} \\ \cline{2-7}  & **R Square** & **F** & **df1** & **df2** & **Sig.** & **Constant** & **b1** \\ \hline Logarithmic & 0.948 & 3273.083 & 1 & 178 & 0.000 & \(-0.132\) & 0.092 \\ Compound & 0.592 & 258.241 & 1 & 178 & 0.000 & \(-0.102\) & 1.009 \\ S & 0.548 & 215.861 & 1 & 178 & 0.000 & \(-1.318\) & \(-4.951\) \\ Growth & 0.592 & 258.241 & 1 & 178 & 0.000 & \(-2.282\) & 0.009 \\ Exponential & 0.592 & 258.241 & 1 & 178 & 0.000 & 0.102 & 0.009 \\ Logistic & 0.592 & 258.241 & 1 & 178 & 0.000 & 9.800 & 0.991 \\ \hline \hline \end{tabular} Notes: The dependent variable is market penetration, and the independent variable is time step.  
\end{table} 
Table 4: Model summary and parameter estimates. Figure 4: Market penetrations of the total target audience at each step. the proportion of PIRs is, the larger the impact of service quality. The results are reasonable since AISs are more adept at judging quality using multiple information sources and are more influenced by their personal judgments of the service quality of the social platform than PIRs. \[MP=0.746Q_{0}-0.651 PP-0.106Q_{0}*PP \tag{7}\]  
with:  
\[\text{R}^{2} =0.992,\text{ F}=99999.00,\text{ t(PP)}=-492.95,\text{ t(Q}_{0}) =-80.22,\text{ t(Q}_{0}*\text{PP)}=62.57\]  
of interaction times, but this positive relationship disappears at a certain level of interaction times. This occurs because platform users have already made all the individuals in their personal social network aware of the platform in the WOM activities caused by the previous interaction, and the subsequent increase in interaction times does not contribute to information diffusion. Since the marginal effect of interaction times is decreasing, we conducted the sensitivity of final market penetration to varying interaction times from 1 to 40 times to deeply test the relationship between interaction times and final market penetration. From Figure 8, we observe an apparently decreasing marginal effect of interaction times on final market penetration. Combining the above results related to valuable output, we found that launching a small amount of interaction with high-quality content is a wiser option for platform managers compared with spending efforts and time launching multiple interactions with low-quality content. Additionally, improving service quality is more valuable when there are more AISs and fewer PIRs. 2. Varying indexes related to information diffusion  
\(\bullet\) Varying seed number  
Figure 9 shows the sensitivity of the market penetration in each step to varying the number of seeds from 2 to 20 with different proportions of PIRs (30%, 50%, 70%). An increase in the seed number contributes to an increase in market penetration. The effect of  
Figure 8: Final market penetration. Figure 7: Market penetration at each step. Since these two strategies are more effective when proportions of PIRs are higher, managers should strengthen these strategies related to information diffusion with an increase in PIRs. 3.