I LOVE how Seller Tools does a lot of work for me such as putting out tweets, adding items to Facebook and Pinterest. It has saved me LOTS of time and gotten tweets out that I probably never would have done myself.
It's amazingly convenient for posting to my shop's Facebook page! I just set it up and then forgot about it which is awesome cause that's the whole point, to save me time and energy promoting my shop while I can direct my attention to other things!
I especially like the promotion tools which has easy schedule set up with all options I need. Saving a LOT of time on a daily basis! Keyword and trend tools give information to think about and to improve the tags and titles, really helpful. And since this is dynamic, you can stay tuned to the changes in the area of your interest with no waste of time for search it in other way.