Personally, I don't think so. Especially not in the digital age that we're in today.
There may have been a time when, perhaps Renaissance masters created stunning works of art that impressed others so much that they'd spend months painstakingly imitating the style and creating similar works of art.
I can see how this can be seen as flattering, because people are investing time and effort to create work that's like the original.
These days though, it doesn't take very much effort to replicate somebody else - especially when it comes to web content, original ideas, business models etc...
If someone were to start up a social Q&A site called www.BlurtThat.com, I think most of us on the original Blurtit would feel less than flattered (that domain name is already registered to one 'Accubase Technologies' by the way).
If you want to flatter someone these days, there are 101 ways to do it! You can ping them an email and tell them how wonderful they are (my inbox is full of stuff like that), or you can 'like' their page on Facebook, follow their Twitter account.
Sharing on social media is a perfect example of how we can all do better than mere imitation. I remember seeing a makeup artist complaining on Facebook that another user had been uploading pictures imitating her work (from which she makes a living).
In this context, I think the original artist would have felt far more flattered if someone had shared her original photos that she'd uploaded - giving the author credit for them.
Being copied, and watching someone take credit for your creativity (and possibly steal some of your business) is no fun.
Who even came up with the idea that 'imitation is the most sincere form of flattery'?
I had a dig around to see if I could find a verifiable source for this proverb, but there seem to be several possible ones...
One interesting suggestion I found was that it could have religious connotations - based on the popular Christian belief that we're all made in the image of God.
Can we really help copying each other
Before I finish up, I think it's worth noting that imitation is probably a part of human nature. Our survival instincts teach us that, if we see someone doing something that's working well for them - then we should probably try that out too.
And, as someone who was in a band that was once described as a 'cheap version of Marilyn Manson', I can tell you that we all borrow ideas from here and there occasionally.
I guess the important thing is to give credit where credit is due, and accept that, if you're burdened with being awesome, other people will want to be just as awesome as you!