Only paint concrete if it is for a garage or shop type of application, where resistance to grease/oil is the main purpose. The thing is, a garage or shop is out of the weather, and takes much longer to peel.
Don't paint a patio. It WILL peel and crack rather quickly. Probably in about a year if you live higher than the mason-dixon line where temps regularly fall below freezing and snow/ice sits on the patio. After it peels, your only option is to strip it and do something else.
This is why suppliers work behind the counter and get caught up in text book fantasies, even if they make field visits which are usually just an excuse to sell more materials to builders or hacks who don't know what they are doing.
Don't ever paint a garage or shop floor. Ever. Use a two part epoxy.....usually runs about $75/gallon but it's worth it because you won't have to mess with it for years. (Epoxies and paints are completely different products) Garages are usually not heated like homes and the mass in concrete (where ever it is) has an adverse effect on paint causing it to peel because the moisture pushes it up and off the concrete surface.
Moreover, vehicles are usually kept in garages and the weight in addition to the tires are a guaranteed way to rip the paint off. Now add in other factors such as motor oil, lawn mowers, snow blowers, etc. At the end of the day the surface of the floor has taken a hell of a beating from several different substances that all have toxic effects on paint. The epoxy is ten times more durable and can be cleaned repeatedly without the breakdown in paints. It also doesn't make much of a diff if the concrete floor is inside or out because it is always cooler than the air above it.