Concerning pump and dump

In a previous thread on this very site, someone talked about having analyzed pump and dump stocks. What he did was, as soon as he received a stock spam, he went to look at the price and logged that as if he had bought 1000 shares (they're penny stocks, so a few bucks in all).

Then he went back a few days later to find out the new price. One stock in over forty tries had a positive result.

This report (http://papers.ssrn.com/sol3/papers.cfm?abstract_id=920553) is not the thread I mentioned, but the conclusion is quite clear :

"Before brokerage fees, the average investor who buys a stock on the day it is most heavily touted and sells it 2 days after the touting ends will lose close to 5.5%."