Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Short selling - lender's motivation
Oftentimes, the lender (the owner of the security) is not explicitly involved in the lending transaction. Let's say the broker is holding a long-term position of 1MM shares from Client A. It is common for Client A's agreement with Broker A to include a clause that allows the broker to lend out the 1MM shares for its own profit ("rehypothecation"). Client A may be compensated for this in some form (e.g. baked into their financing rates), but they do not receive any compensation that is directly tied to lending activities. You also have securities lending agents that lend securities for an explicit fee. For example, the borrower's broker may not have sufficient inventory, in which case they would need to find a third-party lending agent. This happens both on-demand as well as for a fixed-terms (typically a large basket of securities). SLB (securities lending and borrowing) is a business in its own right.  I'm not sure I follow your follow-up question but oftentimes there is no restriction that prevents the broker from lending out shares "for a very short time". Unless there is a transaction-based fee though, the number of times you lend shares does not affect "pocketing the interest" since interest accrues as a function of time.