Exchange Ratio Calculation
Exchange ratio, a common term used by banner exchanges,
measures how often a member's banners are displayed. Our exchange
ratio starts at 0.67 (or 3-to-2). That means for every three banners
displayed at your site, our server will display your banners at least
twice at other sites. But that's not all.
Besides hit credits, other factors also affect your exchange
ratio. Each of them plays an important role in the calculation. If
your exchange ratio should fall below the mininum 0.67, please read
through the following sections for clues.
Hit credits is the most important factor in deciding your exchange
ratio. Generally speaking the exchange ratio will approach 1.00 when
you maintain eight hit credits or more in your active account. All
members with the same amount of hit credits should receive the same
base impressions. Beyond that, the number of banners being displayed
at their sites will earn them additional impressions.
For example, consider two members A and B both having 20 hit
credits, which translates to 10 base impressions per day. If member A
only displays 2 banners today at his site, our server will display his
banner 10 times at other sites. But for member B who displays 300
banners at her site, the server may display her banner 10 + 490 = 500
times. Member A's exchange ratio is 5.00, which is much higher than
member B's 1.67. But member B receives more impressions overall.
We cannot predict the base impressions for any given level of hit
credits. It depends on the amount of hit credits that are currently
in circulation. If the average hit credit is higher, then the base
impressions will be lowered for those with less hit credits. It is a
good idea to maintain at least 5 hit credits in your active account.
Of course more would be better.
The click-thru ratio (CTR) of your banner can negatively
affect your exchange ratio. CTR is the average number of times a
banner is displayed until it has a click-thru. When a banner is first
uploaded, we assign it a CTR of 150:1 until its first click-thru.
If the combined average CTR for your banners is too high, then
your exchange ratio will be lowered. The high CTR indicates that your
banners are ineffective by design, so we will show them less often
until you re-design them. This prevents members from becoming
careless about the effectiveness of their banners and relying solely
on their hit credits.
On the other hand, members with good banners, i.e. low CTR's, are
rewarded with slightly higher exchange ratios. These banners benefit
all members because they earn more hit credits for the sites that are
The combined average CTR is weighted by the display probability of
each banner. For instance, if a member has two banners which have
display probabilities of 100% and 50%, the CTR for the first banner
would be counted twice as much. If the CTR's are 40:1 and 80:1
respectively, the average CTR will be 66.7:
(40 * 100 + 80 * 50) / (40 + 80) = 66.7.
When one of your banners has a CTR of 200:1 or higher, you should
consider re-designing it. See our
Banner Design Tips page for
tips and links.
Poor targeting may work against you. For example, if you target
only one category and it contains very few sites, then your banners
will be displayed less often than if you had targeted more sites. So
be careful not to be too restrictive.
Banners at Your Site
The banners being displayed at your site also affect your exchange
ratio. You should consider them as a key factor in improving traffic
to your site. By placing the banners on more pages and better
locations, you can increase hit-credit earnings from click-thrus.
Account On Hold
When your account is on hold, we will continue to track the number
of banners displayed at your site and save any undisplayed
impressions. But after the first day of being on hold, your exchange
ratio will drop to the minimum 0.67.
For example, suppose you have enough hit credits to give you an
exchange ratio of around 1.2. On the first day that your account is
on hold, your site displays 100 banners. So we will save 120
impressions for display later. But if your account is still on hold
for another day, we will only save 67 impressions, assuming you also
display 100 banners on the second day. When your hold is cleared on
the third day, we will display your banners 187 (120 + 67) times to
make up for the lost days.
We implemented this rule because in theory, a member may leverage
his or her hit credits -- collecting undisplayed impressions without
spending any hit credit. The proper way to accumulate hit credits is
through the savings account and automatic transfer. See the Hit
Credit section of your account for more information.