Google dumped an incredible amount of money into Allo's marketing at my (large state) university -- they plastered many buildings with full-length advertisements, filled all of the local businesses with pamphlets, and even drove students around campus in weird little (electric?) buggies[1].
Despite all that, I don't think I know anybody who installed (much less regularly used) Allo.
Edit: They also bought Snapchat filters that were geofenced to the campus.