DRIP concept

http://forums.redflagdeals.com/discount-brokerages-drips-how-they-processed-2079423/

There are two types of DRIPs: treasury and synthetic. Brokerages may support one or both types.

Treasury DRIPs are offered by some companies. New shares are issued by the company instead of paying out the company's cash, and some companies offer a discount to encourage shareholders to sign up. If you hold your shares at a brokerage, it takes the company a few days to issue the shares and send them to the brokerage. Then the brokerage needs to add the shares to everyone's account. I'd expect that shareholders at different brokerages that support treasury DRIP would get the same price.

Synthetic DRIPs are offered by some brokerages. The broker takes the cash dividends and buys shares at the market price. Then they add these shares to everyone's account (which should be a faster process than treasury DRIP). Since each brokerage does this independently, shareholders at different brokerages may get a different price and this price would be different than the treasury DRIP price (if the company offers it).

From wechat:

Broke那裏的都是合成drip， 正宗drip是在computershare或Mellon那裏直接注冊，不過你得先找種子過戶時間比較長，先找你附近的drip俱樂部。