What matters when evaluating the popularity of the gift card of a certain brand?
Obviously, the attractiveness among users is one of the key factors. We measure this by counting number of the clicks for each brand from giftcardwiki.com, and then rank them accordingly.
The number of available cards in the market also matters. We could just take the market cap of each brand and rank them, but we feel that doesn’t reflect the true factor. Because some brands might have a large inventory, but their daily buy and sell volume are low. Therefore, we use liquidity (daily buy + sell volume) as the market popularity measurement.
Finally, whether a brand is popular historically also has an impact. This factor also helps to smooth the popularity change throughout time.
Each of the above 3 factors take the equal weight when contributing to the final rank. Here comes the math
current_rank = previous_rank + user_rank + market_rank
where
user_rank is sorted by the count of the number of user clicks on each brand
market_rank is sorted by average daily buy + sell volume on each brand
Below is the example of top 10 most popular brands. (all ranks are normalized to [0, 100] range, lower rank number means more popular) Ranks are currently updated monthly, although we are thinking to update it more frequently.
+--------------------+--------------+---------------+-----------+-------------+
| brand | current_rank | previous_rank | user_rank | market_rank |
+--------------------+--------------+---------------+-----------+-------------+
| Target | 0.00 | 0.00 | 0.16 | 0.00 |
| Walmart | 0.13 | 0.16 | 2.35 | 0.66 |
| Toys R Us | 0.27 | 0.32 | 1.88 | 1.19 |
| Best Buy | 0.40 | 1.42 | 0.63 | 1.86 |
| Staples | 0.53 | 1.90 | 0.31 | 2.12 |
| Macy's | 0.66 | 0.95 | 2.66 | 1.06 |
| Lowe's | 0.80 | 0.47 | 4.23 | 0.40 |
| Old Navy | 0.93 | 1.11 | 1.72 | 2.39 |
| Home Depot | 1.06 | 0.63 | 4.39 | 0.27 |
| Sears | 1.19 | 2.69 | 1.25 | 2.65 |
+--------------------+--------------+---------------+-----------+-------------+