I have an assignment which related to the research name "Propagators, Creativity, and Informativeness: What Helps Ads Go Viral" (I'll leave the link below). However, when it comes to this section, I am a little confuse with the outcome of the model 3, especially that b value.

As it confirms the three way interactions of three variables, I am wondering what does that b=100.11 stand for?

Pls help me with this question, my assignment is getting nearer to the due day.

Thank you so much for your help.

Link to the paper: DOI: 10.1016/j.intmar.2019.02.004