Tracking orders back to their sales origins
You can accomplish this without using Google Analytics but, rather, by merely using E-junkie's built-in features. The values identifying your sales sites/pages that you track by this method would appear in your E-junkie Transaction Log.
Tracking orders from different sales sites
You can do this by adding a&custom= parameter to all your buttons' href= URLs, where all the buttons on a given site have the same custom value, which differs for each site -- e.g., if your standard button code looks like this example:
<a href="https://www.e-junkie.com/ecom/gb.php?c=cart&i=XXXXXX&cl=YYYYYY&ejc=2" target="ej_ejc" class="ec_ejc_thkbx" onClick="javascript:return EJEJC_lc(this);"><img src="https://www.e-junkie.com/ej/ej_add_to_cart.gif" border="0" alt="Add to Cart"/></a>
...then for all the buttons on your sales site at example.com, you would add a &custom=example.com value like this:
<a href="https://www.e-junkie.com/ecom/gb.php?c=cart&i=XXXXXX&cl=YYYYYY&ejc=2&custom=example.com" target="ej_ejc" class="ec_ejc_thkbx" onClick="javascript:return EJEJC_lc(this);"><img src="https://www.e-junkie.com/ej/ej_add_to_cart.gif" border="0" alt="Add to Cart"/></a>
...whereas all the buttons on your other sales site at othersite.com would get a different &custom=othersite.com value like this:
<a href="https://www.e-junkie.com/ecom/gb.php?c=cart&i=XXXXXX&cl=YYYYYY&ejc=2&custom=othersite.com" target="ej_ejc" class="ec_ejc_thkbx" onClick="javascript:return EJEJC_lc(this);"><img src="https://www.e-junkie.com/ej/ej_add_to_cart.gif" border="0" alt="Add to Cart"/></a>
Note that &custom= values can be any string of letters and numbers, so you're not strictly required to specify a site domain as in the examples above -- e.g., if you prefer, you could just use something like &custom=A on one site and &custom=B on the other.
Tracking orders from different sales pages on the same site
The instructions above will also work if you're using Buy Now buttons (rather than Cart buttons) on different sales pages of the same site, though you'd specify some other page identifier like &custom=somepagename instead of the site domain; however, since only one &custom= value can be tracked per entire order, that approach isn't well suited where you have Add to Cart buttons on various pages and wish to track what specific sales page each item was added from. In this case, you could manually add Variations values parameters such as &on0=via&os0=somepagename to each button's href= URL, identifying what page the item is on, like so:
<a href="https://www.e-junkie.com/ecom/gb.php?c=cart&i=XXXXXX&cl=YYYYYY&ejc=2&on0=via&os0=somepagename" target="ej_ejc" class="ec_ejc_thkbx" onClick="javascript:return EJEJC_lc(this);"><img src="https://www.e-junkie.com/ej/ej_add_to_cart.gif" border="0" alt="Add to Cart"/></a>
Note that if your product is already using Variations to let buyers specify one or two product options, you'd need to use different parameters in your button URL; if your product already has one option using Variations (e.g. Size), use &on1=via&os1=somepagename, or if it has two options (e.g. Size and Color), use &on2=via&os2=somepagename. This does not pertain to options using "Variants affecting price/weight/stock/SKU".