I believe samples at 50/50 and 24mg strength. Samples of 'new' flavors need weeks for me, no different than new bigger bottles. Others can wait less I'm sure but I tend to play it safe. I have a big pill bottle here with 10 samples in it. The top row of 5 has hit 6 weeks and I've started trying them. The bottom ring is between 2 to 4 weeks. Haven't even touched them yet. I know that a number of flavors I like require 6 weeks for me of steeping. So I just keep samples around that long also.
My suggestion: Since you'll want to expose the sample bottle to the air to get the steeping started drip 3 or 4 drops onto an atomizer and see what you think of the taste. If you dislike/hate/can't taste it put it aside and try in 2 weeks. Then 4 and finally 6 if you're like me. Stop waiting if you find you like it.
Just as an example. Rocking chair was just released 2 or 3 weeks ago. Got a sample with my order the week it came out. Tasted nothing but 'chlorophyll green,' that bitter taste stems and twigs and other green plant bits have. Re-tried the bottle this past weekend. The chlorophyll green taste is completely gone and I taste a hint of sweetness and a few flavors but its all extremely weak. So I can tell this flavor will take at least another 2 weeks for me to give it an honest evaluation.