Time to Percolate
How long should you stick with a tactic before you switch to a different one? I typically recommend sticking with something between 30 and 90 days.
I know 12 weeks seems like a long time particularly for something that may not end up working, but this is why it is important to have some insight, data, or customer based feedback that the tool or tactic you are trying may produce beneficial results.
When you start a new tactic, that is when you decide the minimum duration you will stick with it. You shouldn’t be making this decision a week after implementing and not seeing any results. Give it time, stick with your plan so you truly have an idea if it ends up working for your store or not.