This may seem tangential at best, but...

Speculation as an economic activity and gambling have similarities but are qualitatively different; but still, they interpenetrate in some cases.

For more on the similarities and differences, see the write-up I did in "Speculative Capital"; for another distinction, here is something from Edward Chancellor's extensive but generally disappointing Devil Take the Hindmost: A History of Financial Speculation (despite the title, and the author's various protestations, it is mostly a catalog of manias and general capitalist excess and greed and other departures from the day-to-day dullness of the bulk of speculative activity):

"Economists differentiate gambling and speculation on the grounds that gambling involves the deliberate creation of new risks for the sake of diversion while speculation involves the assumption of the inevitable risks of the capitalist process. In other words, the gambler places a bet on a horse he is creating a risk, while the speculator who buys a share is simply inovlved in the transfer of an existing risk." (pp xii - xiii)

Okay as to the interpenetration, since gambling does involve money and the accumulation or the pooling of money, in many cases the "house" (whether a state or casino or host of the game) has come to function as a bank, that is, an accumulation of capital that can then be used invested in more routine economic activity.

Lotteries have historically (often) been used as a way of accumulating capital for extensive projects where the financial system (e.g., raising money through bonds) is primitive or non-existent; e.g. U.S. colonial-era projects for Harvard, Yale, Princeton and other colleges.

A historically interesting spin on this is described in Kings: The True Story of Chicago's Policy Kings and Numbers Racketeers by Nathan Thompson (2003, The Bronzeville Press, Chicago). In Chicago's black community, the mainstream banking system was for the most part inaccessible to the community. Thompson describes how the "policy kings" -- the people who ran the numbers (or "policy")games, basically illegal or quasi-legal daily lotteries, became the holders of pools of money that could then be lent out to the community -- i.e., they became the de facto bankers for the community.

"Policy became the biggest Black-owned business in the world with combined annual sales sometimes reachng the $100 million mark and employing tens of thousands of people nationwide. In Bronzeville [the heart of Chicago's black community - jd] Policy was a major catalyst by which the black economy was driven ... Policy Kings underwrote the establishment of several private dental and medical practices for professionals facing lack of placement options due to racial discrimination." (pp 13-14) As Thompson told the Chicago Sun-Times, "They were the bank that aspiring African-American businessmen and women could go to when they couldn't go downtown... They were a ready source of venture capital."

Later in his book Thompson describes legitimate businesses created by "policy kings", funded by the policy game; also the "kings" provided a social insurance function.

I should say that simply re-investing money into productive enterprises is not "speculation". But the financial function of investment eventually ties into the bigger world of speculation, the trading of financial instruments for gain; or, the buying and selling of risk. This needs to be worked out more...

How does all of this tie into networks? (a) Economies are networks (b) speculation comes into its own as a dominant aspect of the economy because of the globalized economy made possible by electronics and (c) the electronic-based communication networks that allow "network effects" to come to the fore. For a start.

jd