I am puzzled-there are something in excess of 800 investment newsletters. Are any of them really reliable? (By reliable, I mean, does the leter give advice that actually result in you achieving above average investment gains)?
It seems to me that , there should be good and bad investment advice-and that over time, the “bad” ones should disappear-whereas the “good” ones should gather more and more subscribers-so that the advice they offer becomes less and less valuable.
Hence, the formerly good ones should revert to the average market returns.
Are there any studies of these newsletters? Is it possible to score abaove-market gains, by latching on to a “good” one, and staying for 2-5 years (before they revert to the mean)?
Finally, the great “paradox of all such advisors” why would a successful advisor want to share is secrets? Why not just invest for yourself, and get all the gains for yourself?
Is this proof that most of these advisors are scams?
The Hulbert Financial Digest is what you are looking for. It is a newsletter that ranks most of the other financial newsletters. Mark Hulbert has been doing this for decades and has a pretty good reputation, from what I’ve heard.
I don’t subscribe, but I SUSPECT what you are going to find is that no other newsletter consistently beats the market. If one did, all of the money would flow to that newsletter, depressing its results and driving it back toward the mean.
My conclusion after several decades of investing: the Index Fund pushers are right. There is no low-risk way to beat the market. The best you can do is match the market in a low-cost index fund (or ETF). I don’t mean to burst your bubble, but that’s how I see it.
Note that when I first started investing, I thought “I’m a bright guy with an advanced science degree from an Ivy League University. I should be able to figure out some way to outperform the market.” But I wasn’t and I have a lot of financially painful “experience” that proves it. 
I’m not telling you what to do. You’ll have to learn that yourself. When you get tired of losing money, come back to indexing. It’s a lot less stress, hassle, and aggravation.
J.