I understand the aesthetic value in using tabs, and in my experience have never had an issue using JQUERY or AJAX to display content and later seen a drop in ranking or banishment.

That being said, if each tab represents a completely different page of content (for example: Services, Company Information, Product A, Product B, etc), you’re faced with a completely different issue.

Each “Page” should contain page-level structure if you wish that page to rank well in the SERPS. This structure includes having a unique title, meta description, heading (h1) and unique (and hopefully exciting) content.

Essentially, you’re dumping apples, oranges, pears, and tomatoes into one bucket with one label on the outside that either says “Apples” or “Fruit”. Your competitor who has his produce in separate buckets is providing a better experience to the shopper at the end of the day.

If you’re using tabs to display subheadings of a main topic and the source code displays all of the subheadings with respective content, but does not display the content to the user until the tab is clicked, you’ll be just fine. If your website were to be reviewed by a Google Search Quality Engineer, they would most-likely NOT have an issue since you are not purposefully trying to game the system, but instead just providing a simple navigation schema within a page of content.

Hope this helps?