Question: Show how to modify Example by changing the bids and/or budgets to make the competitive ratio come out as close to 0 as you like.
Example: Suppose there are two advertisers A1 and A2, and one query q. The bids on q and budgets are:
Bidder Bid Budget
A1 1 110
A2 10 100
If there are 10 occurrences of q, the optimum off-line algorithm will assign them all to A2 and gain revenue 100. However, because A1's budget is larger, Balance will assign all ten queries to A1 for a revenue of 10. In fact, one can extend this idea easily to show that for situations like this one, there is no competitive ratio higher than 0 that holds for the Balance Algorithm.