This is a sign advertising is on the decline in that area. If it was such a great medium the company wouldn’t be foregoing revenue to put their own “hey you should advertise here” bullshit.
I’ve heard in Regina, many billboards have a 6 month wait list to get on them (though this isn’t verified) and I don’t think I’ve seen an advertisement promoting billboards on a billboard in Regina for a long time.
In Palm Springs however, you see many billboards talking about how great billboards are. It’s their low tourist season right now so no wonder advertising on billboards isn’t in high demand.
The next time you see a billboard advertising about how good they work, you now know exactly what they’re actually saying.