Good question, and it's a mixed basket, really.
Back in the day, I did commercial web design for clients, and offered hosting as an afterthought, which became a small amount of secondary income. Then I set up my series of sites and sold local ads, which became a third leg. Then I brought in Adsense, which became a 4th leg.
Over time, web design died away as templates got better, to the point that I don't even market it anymore... which takes me back down to 3 legs of revenue. But I have about 120 hosting clients, ranging from $8.95 to $14.95 /month, so they cumulatively bring in about $1,200 USD /month.
But this year, Adsense has gotten weaker and weaker (literally about half of what I made from it last year, even though traffic is higher), so now I'm focusing on the other 2 legs of the business: locally sold ads, and hosting.
But lately I've been losing clients to Wix and GoDaddy, because they're cheap and the client can easily do it themselves. So to compete, I'm going to have to come up with a similar option; otherwise, my business will have gone from 4 legs of revenue to 1 (the locally sold ads). And that's scary.
Worse, a lot of those hosting clients were sold on "get a website, domain, hosted, and an ad on a local site, for $500 /year". When I lose their hosting account, I also lose the local ad... so it becomes more than just the $8.95 for hosting that's lost.
If I could find a good template program that any monkey could use, I could start promoting a "free website with ad" package again. But as it is, I'm kinda stuck with the inability to grow.