This is hard for me to believe. 20 years ago, my neighbor, a devout christian believed Popoff. Oneday, he announced over the radio that there is alady who has financial stress. God is telling you today that if you send $500, today, God will multiply this. Well, she believed this and sold whatever she had and sent $500. In 2 weekss, she won a lottery for $5000. Is this luck? Rare coincidence ? Or this had nothing ot do with Popof?
In the last 20 years, thousands of people have sent money to Popoff, sometimes in large quantities on similar promises (how many ladies had financial stress in 80s? Plenty). Most of them did not get freebies in the form of gambling profits or other chance windfalls. Some did, and some of them did it within some 'significant' time frame of giving Popoff or somebody else (sacrifice to Satan, Allah, their agents or L. Ron Hubbard etc etc).
So the answer to the question is 'insufficient evidence to make any positive claim'. To make a positive claim for Popoff's legitimacy we'd need a study. We'd need to hear from a significant proportion of Popoff's donators, with evidence of any claimed fortune. We'd need to see a group of people who simply came across fortune without any donation. Then we could see if giving a donation gives one a tendency towards being fortunate.
In short, your anecdotal sample of 1 is completely useless. It tells us exactly what we already knew: people win lotteries and some of those people might have engaged in some superstitious ritual before hand.
What it does not tell us is whether some superstitious rituals actually have any effect on success.
Rare coincidence ?
No: a common one.