N社はスポーツ用品の小売販売業者で，実店舗販売の他，インターネットのショッピングサイトを利用した通信販売も行っている。ショッピングサイトのサーバの運用は外部に委託しており，毎月，委託先からアクセスログの分析結果が報告されるので，この報告に基づき，サイトの運営や改善に当たっている。 ショッピングサイトのトップページから商品購入手続完了に至る経路は，図1のとおりであり，図1中の矢印はリンクの経路を示す。ここで，A～Fは矢印の元のページから先のページへのアクセス率である。例えば，トップページにアクセスした利用者のA%が商品紹介のページにアクセスし，商品紹介のページにアクセスした利用者のC%が購入手続のページにアクセスしていることを示している。また，トップページへの外部からのアクセス件数に対する購入手続完了の件数の割合をコンバージョン率といい，先月のコンバージョン率は5%であった。 N社では，広告によるショッピングサイトへの集客策として，1か月のバナー広告と1回のメール広告を比較検討することにした。二つの案が次のとおりであるとき，これを比較した内容として，適切なものはどれか。ここで，各案のクリック率は，表示された広告や送信されたメールの数に対する，N社ショッピングサイトへのリンク数の割合である。コンバージョン率は，当該広告からのリンク数に対する購入手続完了の割合で，いずれも過去のデータに基づく予測値である。 〔二つの案〕 A案 C社ポータルサイトで，バナー広告をする。 費用 120,000円/月 広告表示回数 250,000件/月 バナー広告のクリック率 0.8% コンバージョン率 5% B案 D社のメールマガジンに広告を1回掲載する。メールはD社のデータベースを基に，スポーツ用品に関する情報の受信を希望している人にターゲットを絞って送信する。 費用 4円/メール1件 メール送信数 50,000件/回 メール広告のクリック率 5% コンバージョン率 8%
平成25年度 春期 ITパスポート試験 問98
This question's explanation and your answers so far.
問 98
Incorrectア
The number of times the advertisement reaches users is indeed larger for Proposal A (250,000) than for Proposal B (50,000), but the number of users who visit the shopping site is determined by the number of clicks. Proposal A gives 250,000 × 0.8% = 2,000 and Proposal B gives 50,000 × 5% = 2,500, so Proposal B brings more visitors. Even when the number of displays (emails sent) is large, traffic does not grow if the click rate is low, so the conclusion that “Proposal A is more effective for increasing the number of visitors” is the opposite of the calculated result and is wrong.
Incorrectイ
The number of completed purchase procedures is 2,000 × 5% = 100 for Proposal A and 2,500 × 8% = 200 for Proposal B, so Proposal B is twice Proposal A and is not inferior to it. Proposal B does send fewer emails, but its click rate of 5% and conversion rate of 8% are both higher than Proposal A's (0.8% and 5%), so it comes out ahead in the final number of results. Drawing the conclusion from the small number of emails sent alone is the error.
Incorrectウ
The cost to obtain one click is found as cost ÷ number of clicks. Proposal A gives 120,000 yen ÷ 2,000 = 60 yen and Proposal B gives 200,000 yen ÷ 2,500 = 80 yen, so Proposal B is the more expensive. A high click rate does not immediately mean a low unit cost per click; because Proposal B's total cost is 4 yen per email × 50,000 emails = 200,000 yen, it loses to Proposal A on unit price. Concluding that the unit price is cheaper from the high click rate alone is the error.
- エ
正解 The correct answer is エ. The cost-effectiveness of internet advertising is compared using the acquisition cost per result, that is, the cost spent divided by the number of results. First, work out each proposal's cost, number of clicks, and number of completed purchase procedures in turn. Proposal A costs 120,000 yen per month; multiplying the 250,000 ad displays by the click rate of 0.8% gives a click count (number of links to the site) of 250,000 × 0.008 = 2,000, and multiplying that by the conversion rate of 5% gives 2,000 × 0.05 = 100 completed purchase procedures. The cost per completed purchase is therefore 120,000 ÷ 100 = 1,200 yen. Proposal B costs 4 yen per email × 50,000 emails sent = 200,000 yen, its click count is 50,000 × 0.05 = 2,500, and its completed purchase procedures are 2,500 × 0.08 = 200. The cost per completed purchase is therefore 200,000 ÷ 200 = 1,000 yen. Since 1,000 yen < 1,200 yen, the cost to obtain one completed purchase procedure through advertising is cheaper for Proposal B, so エ is correct. The key point is that although Proposal B costs more in total than Proposal A (200,000 yen > 120,000 yen), both its click rate and its conversion rate are higher, so it works out cheaper when viewed per result.
- Definitions and use of the click rate and the conversion rate: click rate = number of links to the site (number of clicks) ÷ number of advertisements displayed (emails sent); conversion rate = number of completed purchase procedures ÷ number of links from that advertisement. Therefore the number of completed purchase procedures = number displayed (sent) × click rate × conversion rate, obtained by multiplying the two rates in turn.
- Compare advertising proposals not by the total amount but by the acquisition cost per result (cost ÷ number of results). The unit price per click and the unit price per completed purchase are different measures, and which proposal is better can be reversed between them (here the cost per click is cheaper for Proposal A at 60 yen, while the cost per completed purchase is cheaper for Proposal B at 1,000 yen). When comparing unit prices, always check whether the denominator is the number of clicks or the number of results.