There doesn't seam to be a documented upper limit for the number of switches that can be daisy chained. However, the impact of chaining too many switches (say above 6 or 7) would be slow downs or delays (increased latency) specially when data comes from the far end of the chain. Slowness, not only in delivering your data traffic but also for control traffic. For example, STP might take much longer to discover loops. You can notice this when a cable is just pluged into a port, the amber light will stay longer on the port before it turns green.
A start topology is probably more efficient if you have more than 4 or 5 switches. Put the most powerful switch at the center and connect all other switches directly to it.
Thats as far as I know.
