IdeaStarter Pro does not limit number of products and categories. It does not limit category nesting as well.
However, you should take in account your server performance as IdeaStarter Pro is optimized for smooth performance with up to 20 000 products. More products you want to have - better and more powerful server you will need to hire.

If necessary, you can limit access to some categories in your store by the customer's membership levels. Any category can be made members-only (visible only to the customers with a certain membership). Ordinary customers will not be able to see such a category on the storefront, nor to find/view/order products from it.

Enhance your sales by bringing out info about what's hot! Draw your customers' attention to featured items and seasonal products: put any products on display in the 'Featured products' box on your homepage or on any level within categories. Control the selection of products and the order in which they need to be shown

Inform your customers what products in your store sell best. Free Bestsellers module automatically generates a list of best selling products in a special Bestsellers box on the store-front. Products get into the list based on the results of the store sales analysis. In the period when the store has just been launched and there have been no sales, the contents of the Bestsellers list is formed of the products which get the most views.

Multiply your profits by upselling selling additional products to customers at the time they are about to place an order. Try to anticipate your customers needs and help them to reach their goals: while the customer is in a buying from you frame of mind and is viewing the details of some product, recommend to him additional products which are in some way related to it. Products can be easily associated with one another so that related products are displayed in a special section on the product details page of the product to which they are related. If, purchased in combination with these additional products, the original product turns out more useful, the customer satisfied with the solution offered to him at your store will be more inclined to buy next time from you.

Alongside basic search that allows your customers to find a product by a fragment of its title, description or the contents of a custom extra field, there is advanced search which your customers can use to search for a product by its category, manufacturer, SKU and the price/weight range to which it belongs.

Enable your customers to quickly access the products they need. Specify the manufacturer/brand name for each of the products in your store and provide a list of available manufacturers in the Manufacturers menu. Your customers will be able to view all the items produced by the same manufacturer in one list.

The contents of the products list (manufacturer products lists included) can be sorted by SKU, product titles and price. A customer only needs to click the appropriate sorting link at the top of the products list area so the products are rotated and displayed in the necessary order (for example, clicking the Price link sorts products according to the decrease of the product prices). Clicking the same link once again reverses the order of the products in the list (continuing the previous example, clicking Price another time gets products to be sorted so their prices are displayed in ascending order). The original sorting order can be restored at any moment by clicking on Default.

Fast Lane Checkout module provides a more user-friendly and intuitive checkout procedure in IdeaStarter Pro.

X-Magnifier add-on allows to to view, pan and magnify big size and high quality images (GIFs, JPEGs and PNGs up to 2000 px size). Moreover, there is no quality loss when zooming, so all product details can be shown to customers and website visitors from different points of view. Also, customers are able to drag and pan images.