Paid search generates traffic, but ecommerce businesses live and die by profit. When you’re not sure why the traffic that your paid search program sends to your site doesn’t result in cash in your coffer, it could be one of these seven reasons.

1. Your keywords are too generic. If you sell light-blue, small widgets, for example, take care bidding on broader keywords, such as “widgets.” Make sure your core keywords – like “light blue small widgets” – convert before expanding your keyword base. If they don’t, you need to dig deeper to find the culprit.

2. Your Return on Ad Spend (ROAS) goal is too high. Keep the lifetime value of a customer in mind when planning what your target ROAS goal should be. If your ROAS goal is 500% (meaning that you want to gross $5 for every $1 in ad spend), but you know your average customer buys from you three times during their lifetime, you may want to consider lowering your ROAS goal. You will pay more per conversion now, but the repeat purchases with no associated ad spend will boost your bottom-line profits.

3. Your pricing is not competitive. If your competitors sell similar products at lower prices, you may not convert well. Searchers can price match products in a matter of seconds because your ad is right next to a dozen other paid and organic links on the search results page. If your pricing is not at least in the ballpark, well… yer out!

4. You don’t offer free shipping. Amazon and other big players have set new expectations in consumers’ minds: Shipping should be free. You could be hurting your conversion rates by not following suit. If you can’t cover shipping for every order, try it out. Consider using it as a reward to increase the customer behaviors you want to see more of, such as larger cart size – “Free shipping over $75,” or “Buy three and it ships for free.”

5. Your purchase process is too long. Conversion rates drop as the number of steps in the purchase process increases. Streamline the purchase process by removing as many steps and entry fields as you can while still collecting the data you need to complete the sale. In addition, make certain that the “Add to Cart” button is clearly visible in the first pageview of every product page. Don’t make visitors work to find it.

6. Your site isn’t mobile friendly. Check the traffic by device in your PPC performance reports and scale your device bids accordingly. Quite often reducing mobile bids 50% or more brings mobile traffic into a more profitable zone. For example, if your bid for the keyword “light blue small widgets” is $2, your mobile bid may need to be adjusted down to $1.

7. Your site loads too slowly. People are extremely impatient. Most visitors will just bail out of your site unless the pages load within three to five seconds. Why would they wait when it’s easier to go to a faster site? As much as having a slow site impacts your paid search conversion, it’s guaranteed to be dragging down conversion rates across every visitor that comes to your site. Perhaps it’s time to tackle the challenge of optimizing your site speed. Google’s PageSpeed Insights tool is a good place to start.

There could be other reasons specific to your business that your PPC doesn’t convert, but these are the seven most common reasons.