Design Best Practices

[Jackie Young]

If there is a great deal of traffic on a website, are there advantages to creating separate databases to hold information accessed by the website, or will tables within the same database suffice (for speed of response, no time-outs)?

Example 1: A single database is created to hold all information for a classified ad site. The database contains 5 tables:
1) Sellers (Key = SellerID)
2) SellerPics (Key = SellerID)
3) Listings (Key = ListingID; Index = SellerID)
4) ListingTmp (Key = ListingID) [holds listings until payment is complete; then moves the listing to Listings, and deletes the associated line]
5) ListingPics (Key = ListingID)
In the event of the site getting much traffic, would it be better to break out each of the above tables into separate databases, or will tables suffice?

Example 2: A single database is created to hold all of the counties and cities within each state, to be used to create drop-down lists on website pages. The database contains 50 tables (one for each state), and 3 columns in each table (zip, city, county). In the event of the site getting much traffic, would it be better to break out each of the above tables into separate databases, or will tables suffice?

Thanks so much for any help you can provide. It is much appreciated!