I don't know how/why people do this, but as some of you know, there is a cottage industry for buying/selling play chips from online poker sites. I personally am using this mode to help fund future custom chip purchases.
My transaction today was for 3 million chips for $11 per mil in PayPal funds. Minus the transaction fee, my net was $31.74 USD.
I sold 5mil last December for about $60. The current exchange rate appears to have dropped a tad; perhaps we're flooding the market.
My play chip mega roll is on P*; I don't know if other poker sites' chips are actively traded. I try to keep at least 1mil post-sell to keep the engine running.
Buy Low / Sell High appears to work well for this unusual "virtual" commodity.