With Subliminal Messaging, the corp gain the ability to have a drip economy that is difficult to shutdown. It is especially good in a glacier or trap deck, where the runner will not want to run often.
While it does incentize the runner to run, actually, it is often not worth it for the runner to run for the sole purpose of denying 1 cred to the corp.
The other use of Subliminal Messaging is to fill up the hand of the corp. Without drawing anything, you can dilute your hand if the runner did not run on the previous turn, by getting Subliminal Messaging from Archive clicklessly.
Generally, 2x Subliminal Messaging is enough to get the drip going early enough while not taking too many slots in the deck. By experience, once you have a Subliminal Messaging in hand, you will be using it on average one turn out of two. Considering that most game are about 20 turns or less, Subliminal Messaging is inferior to IPO, because each Subliminal Messaging does not bring extra value, but get the drip going. As such, it is has more worth as a 1x than anything else.
For deck that favor small econ, it might be worth as 3x, for the dilution of the hand, which will help protect whatever else would be in there.
It is nice to see such an old card (2013!), but it show its age. The art is average and does not evocate well the title, and there is no flavor text.