Listen to Sonny, if you try and piece together an identifier from a group of primary keys and then parse out the data after the fact to correlate your winners you're gonna murder the shit out of your server when MySQL (or whatever you use) starts kicking it in the nuts aggregating and reporting the data.
Each variable should be it's own column in an aggregate type table that the SubId derives from. If you have only two variables your table schema would look like:
Code:
SubId (PK) | AdId | OfferId
1 1 1
2 2 1
3 1 2
4 2 2
Your dataset size is going to grow from there depending on the number of factors you test horizontally (offers/ads/lps/etc...) and vertically (variations on a single variable like different ad copies).
So if you added LP variations to the test above your schema and your SubIds become:
Code:
SubId (PK) | AdId | OfferId | LPId
1 1 1 1
2 2 1 1
3 1 2 1
4 2 2 1
5 1 1 2
6 2 1 2
7 1 2 2
8 2 2 2
9 1 1 3
10 2 1 3
11 1 2 3
12 2 2 3
Not normalzing your data to begin with is asking for heartache later.
m2c