Support.com does not have their employee's best interests at heart. They will not go to bat for you with the companies for whom they provide support. You will be paid a below industry standard and static wage that has not changed in almost a decade.
You will be taking live calls on issues entirely unrelated to that which you were trained for, and they will not provide you with the necessary access or training to resolve those issues.
I was hired by Support.com as a Tier 2 internet tech support agent for Comcast, but when I quit 2 weeks ago, I was also required to do Tier 1 work, phone service support, billing support, sales support, activations support all in addition to excessive out-of-scope calls dumped on us without repercussions or accountability. Comcast used us as a catchall to conceal their customer service mismanagement, and Support.com allowed it - for years.
Your schedule also changes frequently, and unless you are able to keep the highest metrics (like I was), you will not be afforded the opportunity to work the same days and times for more than a few months.
Also, in regard to their substandard compensation (before the PR response comes in), they do have a pay for performance system which I factored into my assessment, as I was able to achieve those bonuses nearly every month of my three-year tenure.