Consumers purchasing big-ticket items online can’t be bothered with everyday items like toothpaste and toilet paper.

At least that’s what a new study from search advertising firm HookLogic found.

HookLogic analyzed more than 4.3 million online transactions worth more than $500 million in sales from Jan. 1 to March 1, 2014, across several mass merchant retailers. The study identified three different types of shopping baskets: those containing just durable goods (computers and vacuums), those containing just consumer product goods (canned soda and toilet paper) and those containing a mix of both categories.

Consumers buying only consumer product goods spent an average of 30.5% more on each product than consumers buying both consumer product goods and durable goods, $17.35 per unit compared to $13.29 per unit. The same was true for durable-only baskets. Consumers spent an average of $61.64 on each durable product in a durable only-basket, three times what they spent on durable products in mixed baskets.

However, consumers buying lower-priced durable items appeared most open to adding consumer product goods, especially if they’re related to the item being purchased. For example, a consumer buying a toy may buy batteries. Consumers buying higher-priced durables are not likely to add consumer product goods, the report says.

The study also measured conversion efficacy using a combination of the conversion rate, how many pages consumers viewed before purchasing and how many units they purchased. HookLogic reports this as an index, with a range of 74 to 334 in the categories studied. The larger number the better. The baby and toddler category had the highest conversion efficiency index of 334, with home and garden at the bottom with an index of 74. The average consumer product goods index was 166, compared to the durables score of 97.