They might be but it's possible that the percentage of such interactions that result in a marriage won't offset the lost potential marriages that came from more "classical" forms of interaction. And when I say "lost" I mean when people start focusing more and more on online dating having expectations other than meaningful relationships/marriage.

The question isn't if online interactions can produce meaningful relationships but rather what is the expectation of people that do it this way. Because if the expectation is that online dating is just for one night stands and "fun" then the increase in such interactions won't bring an equivalent increase in marriages.