But think about the "copy first, innovate second" idea.
When your product is a search engine, there already are engines out there and its a category so you have to "copy" the basic functionality of search. Those are the table stakes.
Google innovated with pagerank, but they did this first. By finding the pagerank method, they were able to produce a better search engine... but they didn't just do an inverted index and run with that for awhile and then decide to "innovate" later.
Look at what Apple does. When they did an MP3 player, yes, they met the table stakes of being able to play MP3s. But they didn't just put out a generic player, and then innovate. They figured out an innovation that made the player worth doing in the first place, then they did it. Apple doesn't just copy products, everything Apple makes they do so because there is a unique selling proposition that differentiates it from the rest of the market (at least in Apple's eyes. We may not appreciate the USP that Apple does.)
For instance the key innovation of the iPod was not the clickwheel, but the iTunes ecosystem. Even though iTunes store didn't come out until later, it was the purpose behind the iPod.
I'm not really disagreeing with this article which reviews the similiarities between g+ and facebook.
But I do want to point out that so many companies get the "copy first" part right, but never get around to the "innovate later" part. Copy first is becomming a mantra. Facebook was a copy of The Face Book, in fact. The reason facebook is what it is is that they did get around to innovating later.
The reason there's no competition for the iPod is that the competition never got around to innovating (or in MSFT's case, got around to it way too late.)
Although, I suppose it might be that itunes forms another part of that; I've owned an ipod but never installed itunes. For a lot of people it probably is a big deal though, especially if the only alternative they'd seen was whatever awful thing Sony was packaging at the time.
I'm still not sure that any of the competition have really copied that. At least I haven't seen a replacement yet that really felt equally well done. My guess would be that too many companies think their "innovation" is going to be "it's cheaper" and compromise quality in order to get there.
Apple had a track record of making their own hardware and software work together really really well. MSFT didn't really follow Alan Kay's hypothesis. I would say that is what the heart of Apple's success is, it's reputation for excellent software/hardware integration.
Google's copy-innovate system is going to work because they brought about good integration between their products (for the most part). That is why Google, like Apple, should generate a very good user-fan-base. Which I believe the article pointed out very well.
Keep in mind Apple didn't make that much money on iTunes, at least in the early days. But yes, generally they could foresee that making music part of your computer's function is a ripe idea for a computer company in the early 2000s: music is easily digitizable, and comes before TV shows and movies in a long line of digital transition.
Mostly though, I just think simple, single-purpose devices were in the capability sweet spot for Apple at the time. Other companies couldn't provide the assurance that ripping all your CDs to your computer would be worth it in the long run.
More often than not this approach fails either because of the high cost of migration to potential users or more likely the pet feature doesn't actually appeal to any more than a small niche.
Don't think this necessarily applies to Google in this case. But I think Google can pull together a user base of 10/20 million pretty easily. The success of Google+ will be determined by whether they can get into the 100's of millions.
There's no lesson to be learned here, and anyone who thinks there is needs needs to defrag their own memory. For every article with a headline like this, you'll find just as many that preach the opposite. Both equally valid, and both equally wrong.
It's debatable wether Google copied anything at all. It is possible to approach the same problem from two different angles and reach many of the same conclusions.
Talking about your observations and theories is great and should be encouraged. Dressing them up as anything more than your own insights is cheap and tacky.