Anyone on Rover (or Wag)? I just started a couple months ago....and I'm making a lot of money on top of my normal job. So much that I wish I started way earlier!! I've raised my rates after each booking, and I continue to get booked in my area. You can get booked for fostering at your place, sitting at their house, or even dog walking!
I've been pretty lucky, as all my experiences so far with different dogs have been very positive. I absolutely love having the dogs as company. As a single guy, it is really nice to have them around and to incentivize me to go on more walks.
I speak extensively with the owners before hand to ensure that the dog's behavior is at least decent. I live with roommates, and barking would be a problem. I keep the dogs in their crates and put a blanket over it when I'm away at work, and it seems like that is working to keep them pretty quiet.
Like I said, my experience has been very positive and I've been able to stack a lot more sats with this side hustle. I highly recommend that you try, and if you need a reference when signing up, feel free to ask me and I'll write one for you.