A few things may be at play when your vinyl, or pleather, starts getting sticky. If it's not too old, there's a chance it may just need a cleaning. But if your pleather is old, the plastic coating over the faux leather vinyl may be wearing thin, exposing a sticky, impossible-to-clean residue that's no fun to lounge around on or wear. If you're experiencing the latter, it may be time to replace the furniture or clothing item--or at least try to cover the stickiness with a vinyl restorer.
What's the Difference?
Leather is cowhide that's tanned, cleaned and chemically treated before being used as furniture upholstery or clothing. Pleather, by contrast, is made by adhering, via a series of rollers and heaters, cheap material like cotton sheeting to a thick plastic coating. The high-gloss sheen on pleather furniture is usually the best way of identifying it, though some leather furniture is manufactured to have a high shine. Leather absorbs oil and moisture better than pleather and must be cleaned and treated more carefully. Pleather cleans up much better; because of the plastic waterproofing, stickiness easily can be mopped up -- if it's caused by surface filth and not an aging plastic film.
What's Causing the Stickiness?
Clean your vinyl pleather to determine if the stickiness has been caused by a food spill or sloppy-handed visitor. Mix warm water and dish soap, then dip a rag into the solution. Ring out the rag and scrub your pleather. After a full cleaning, dry the pleather and see if the stickiness persists. If so, you're dealing with an old plastic film that's worn too thin.
Purchase a vinyl-restoring product (available at home-improvement stores) that contains silicon particles which can form a new bond over thin surfaces of vinyl. This could contain the stickiness under a new protective waterproofing. Just know: Your pleather's days are numbered.
Make sure the cleaner you're using isn't the cause of your stickiness problem. Warm soapy water is all that's needed to clean vinyl pleather. If you're using something different, try spraying some of the cleaner on another vinyl surface to see if the same stickiness results. If so, it's time to buy a different cleaner.