Oh I see!
I've done lots of that, locally and as a traveler. Arebelspy does it as a traveler.
What were you wondering, specifically?
For me, the hardest part is that most people think they're doing me a favour by asking me to do it, lol. (This is because I tend to live in small simple homes in extremely wealthy areas, and they assume its an issue of poverty vs preference.) So they think offering me their luxury home is gift enough, lol. (It's not, I don't want the work of a pet or luxury home.) ...and most offer a chocolate bar as payment. The wealthiest offered $25/day when desperate, and that was more for walking their dog twice a day.
I think whether it pays decently or not depends on the saturation of housesitters per area. Now that they can catch free housesitters via online systems, in which the trade helps both parties, I don't know how many are still paying for this.
In my region, it seems like 20 years ago, people paid for housesitting, and now they don't.