The phrase in the agreement under 3(a) reads:
"Marvel hereby grants to Licensee and Licensee hereby accepts the non-exclusive license to utilize the property but solely upon and connection with the manufacture, promotion, sale, and distribution of the articles, products and/or services identified in Section 1(c)........"
I think (don't quote me) that the non-exclusivity issue in the statement merely indicates that other companies may be licensed by Marvel to use the "property"......property being the specified Marvel characters. This shouldn't come as a surprise to anyone, unless they expected that SPNG was securing an exclusive license to use the characters....something no one company could hope to do. The second half of the statement simply limits the products on which SPNG can use the images, again no surprise.
If Marvel was to try and sell a license to SPNG which provided exclusivity on sponges or sponges w/soap in 'em I suspect that would put Marvel in the position of defining the nature of SPNG's products in terms of patent status, etc. that they would probably want no part of. This way SPNG has to worry about such things....if a competitor should secure a similar license from Marvel it would be SPNG's problem to establish that the base product infringes on whatever rights they may be able to estblish.
Pure guesswork.
