What’s your opinion on buying existing profitable sites as a means of quick returns on investment if you know that side of the business?
Maybe you could buy reasonable non big dollar flipped sites at 20x (monthly multiples) what they are currently making on flippa or other sites?
I don't have much experience with Flippa, though I have sold two sites on there. Both of them were utterly destroyed. One was left to expire the following year even though it was a LLL.org and the other had a very high quality link profile, but the purchaser just let it sit for years and it was hacked. In that time the rankings for it completely evaporated. He put a new site on it, shredding all the value and link equity of the old site and it never recovered. I sold another privately, to an SEO company, and they ruined it, even though I specifically told them not to do what they did to ruin it.
I knew another guy who ran a popular sports site. Must have made about $6K (inflation adjusted). He sold it for about $80K (ditto). It was sold to a fairly well-off guy who wanted something for his son to earn easy money. But they had no idea what they were doing and the guy who sold it had no idea of the SEO side. He was merely put on the path by someone who knew SEO. The new owners made a new site and deleted all the old content; all the old URLs gone. It went from X,XXX or more visits to 100 visits per day. The son hammered the site for four years with regular content, but they ruined the site due to lack of basic SEO knowledge. Including time maybe $160,000-200,000 down. The site still exists, but doesn't rank properly in Google, even for its own name.
I knew another guy, this was back in 2006-2009. His game was creating sites, using link spam to get rankings and then selling them on Flippa for around $10K. I assume the guys buying were low-knowledge and wanted easy income. I am fairly sure none of those sites exist now. I don't know what is going on with SEO today, but I assume there are still sellers like that on Flippa. You need to be able to appraise the link profile of the site to know how solid it is.
That guy was part of a circle of guys I knew who had various games to quickly extract money out of the search results. All of them are gone. Virtually all the SEOs I knew are out of business because it became to difficult to do SEO for small businesses. Some time around 2009 Google heavily shifted to ranking brands like Amazon. Before that you could easily game anything if you knew how. I had page one, often position one for [toys], [adult toys], [web design], [SEO], [SEM], [van insurance]. That lasted maybe 3 years before it was all gone. I knew many people who were annihilated in that period.
Directly after that I made a script to automatically bid on paid blogging opportunities for high page rank expired domains I bought for $10-50, rip a paid blog post they'd already paid for out of Yahoo site explorer. It was about 30 minutes work per day for $600 per day (inflation adjusted). Three months later Google annihilated me. All my domains were fried. I set up again, this time offering links privately, but with very small volume , much less than before. This was a sophisticated system, but it wasn't long until Google whacked that game.
Google have made it much harder to rank in search results for a guy with a site. And it's much more competitive than it is was in the 00s. The 00s were a landrush, when a bunch of nerds saw opportunities and some were able to make big money, in some cases for many years, but most of them are gone. I knew one guy who made 350,000 euros per month in the 00s, with one employee and spent 10 months of the year on holiday. He had very big SEO clients, like Booking.com, and was told by Google that he had to stay away from the big boys [because they wanted AdWords money from them]. But now he is 100% fried.
I think anything that is making small amounts of money and is set and forget is a high risk, similar to penny stocks. Any site that is not regularly added to and maintained is liable to be forgotten, decline or be flushed by Google. The lowest bar-to-entry that is solid is content curation:
https://www.rooshvforum.com/threads/web-content-curation-datasheet.35928/
@Handsome Creepy Eel may have other input. He's more up to date with the last ten years.