I've never understood the selling of actions.  They're just commands in a list and I don't think they're particularly customizable to an image.  They act the same from one to the next.  And the ones I see advertised of FB look like scams - taking a dull blurry image and making it sharp and colorful and showing detail that wasn't in the original.

I'm not saying there's not some validity.  I think nicolesy sells some that work well with food photos.

I've never understood the selling of actions.  They're just commands in a list and I don't think they're particularly customizable to an image.  They act the same from one to the next.  And the ones I see advertised of FB look like scams - taking a dull blurry image and making it sharp and colorful and showing detail that wasn't in the original.

Hm. I use self made actions quite a lot, and I have actions that can make details where there are none in the original. That is of course not possible, but it is possible to create artefacts that look like details.
However, I dont use them very often, but what I do use are microstock pop actions, that can photoshop a picture with a click (with many processes involved) so its becomes bright and shining.
And the point is exactly to not customize too much, but standardize your postprocessing so it takes as short time as possible.
The customization then comes from which action I use and how much of it.

I am using Lightroom presets regularly, I have some from Nicolesy, RadLab and checked out the VSCO presets. There is no magic involved in them, all settings could be done by hand, of course. And they don't work perfectly on each an all images. But they can save you making 20 or 25 single adjustments by hand.

I mainly use them as a quick way to try out different processing styles to see which one might work best with the image. Then I might choose one of them as a starting point for further processing.

It also depends about the goals: For stock, most images will require additional processing for sure but for many images outside of stock the result you can achieve with a simple click are pretty good.