Online revenue was up 12.65% in the second quarter for 70 retailer clients of e-commerce technology provider MarketLive Inc. in a same-store comparison with Q2 of 2009.

What’s more, the e-retailers did not have to lure shoppers with low prices, suggest the data released today. Average order size was up 5.4% to $158.53 from $150.42 while the number of units per order was essentially unchanged at 3.42. That indicates the average price per unit sold was more than 5% higher than in the same period last year.

Other positive signs for e-retailers in the quarterly MarketLive Performance Index include visits increasing 15.4% year over year and the conversion rate improving 18.5% to 4.39% from 3.70%.

At the same time, however, the shopping cart abandonment rate increased nearly 1% to 61.1% from 60.5% and the percentage of visitors who left a retail site after viewing just one page went up nearly 7% to 34.1% from 31.9%. “Shoppers continued to be bargain-conscious and visited multiple sites before purchasing,” MarketLive concludes.

The engagement rate—the percentage of visitors who place items in a shopping cart—was little changed at 9.9%.

Comparing the second quarter of 2010 to the first quarter of the year, MarketLive reports:

• Revenue was up 1.1%
• Visits were down 6.7%
• Conversion rate was essentially unchanged
• Abandonment rate was 1.15% lower
• 1-and-out rate went up 7.7%
• Engagement rate declined 2.3%.

The quarterly report compares only retailers that were clients of MarketLive in both the recent quarter and the same quarter a year earlier and that agree to provide MarketLive with access to analytics data. The 70 retailers in the study are thus a subset of the retailers served by MarketLive, which provides e-commerce software and services primarily to midsized specialty retailers.