Hello,
We've done analysis with the allocations and leaks tools as we continuously load ads, and didn't find any leaks. Allocations does go up a bit at the start, but then it plateaus after a while. In the short term, you may see a slight bump in memory as the second ad is still in memory before the first gets deallocated, for example. But in the long run, I hope you'll also find that no memory is actually leaked.
Thanks,
Eric